The one that's got the orange PWR on it I don't know I honestly don't think it will be easy I don't know if you can just pop it out from the front but possibly you need the experiment on a bad radio I'll have to go look and see if I have one most of my cars have aftermarket nonsense in them.
Theoretically yes, but it will probably be a lot easier just to get a used stereo out of another 2007 in a recycler's yard. Just swap the whole module, no disassembly/soldering etc.
I'm going to guess that the worn button will turn out to be just a small piece of plastic that lives in the faceplate there, and pushes on a real electrical button on a circuit board behind it. So if you had access to another like radio with a power button not worn down to the orange, you could take it apart and get the little plastic piece and swap it. You'd probably have to take your existing radio out of the dash and take both radios apart a little to do it. That could be the cheap way to go if you have access to a non-working other radio for cheap. If the other radio works, it would be even easier just to put that one in the dash and call it a day.
You might even get lucky and use the pic on the side of the pee and the r push in and try to lift the button out if that doesn't work do it on the top but it doesn't seem like it would be on the top in the bottom of the button it would be on the sides The pee in the r should have little tabs it just grab the plastic I could be wrong I've seen the space plate off before but it's been a long time I'm taking a few Toyota radios apartment for and like Jeff said you can probably remove the faceplate and just push it out that way but then you've got to have another one obviously to put in this place
Why do you want to replace it. Does it not work electrically or do you want it to be labeled again? If the latter there are a few options for relabeling. Here are two: The easiest would be to carefully paint the whole thing black with nail polish, let it dry, then using a very narrow brush carefully paint "PWR" on with white nail polish. Let it dry. Then paint one last time with clear nail polish. I have done this on computer keyboards and it lasts a reasonably long time and does not chip off or flake off. It will however eventually wear off. (Train yourself to push the part of the button which is not lettered.) If more clear polish is applied from time to time wearing through to the white paint can be delayed. The down side is that it is very hard to paint perfectly clean and straight lettering. Be sure to tape around the button so no polish gets between it and the case. Another option. Paint it black as above. Apply stick on letters like these: https://www.ebay.com/itm/354935237594 but they tend to ooze the backing glue out around the edges or peel off. The letters in that particular set might be too large for the button, but you get the idea. It might stay on better if painted over with clear nail polish. Test the method on another piece of similar plastic as the polish could dissolve the letters. In theory mylar will not dissolve in acetone, but the paint might if it is applied on top. Edit: Added this: My radio doesn't have that button! These buttons are curved. Had they been flat another option would have been to have somebody with a 3d printer make up a little thin "placard", with the text embedded in a different color from the rest of it, and then glue it on. (Imagine a sliver of plastic like a highly modified glue on nail.) Still possible, but much harder when the surface is curved.
Do not use black electrical tape! The adhesive will make a mess and it is likely to become gooey and slide around after the car sits in the sun. The "tape" part is vinyl and should be good to 200F or so, but the adhesive may soften well below that. Polymerized nail polish should be reasonably heat resistant. I don't know how hot it can go, but expect it should be good up to something like 105C. There are also companies which make custom vinyl stickers that go over car buttons. Never tried those myself. They look like a PITA to apply, as at least some of them have to be sort of baked on with a hair dryer, and they may need each precut letter to be carefully pried up first with a scalpel blade and tweezers. (Hair dryer rather than heat gun as the latter will melt the plastic underneath.) And I don't know how well they hold up. But they are very sharp (edgewise) when applied successfully. I wish that car companies would use double shot buttons rather than cheaping out and just painting the letters on. Then if the button wore down you could still see the same color letter on the same color background. The big unknown in all of these repairs is that the plasticizers in the underlying plastic will slowly leach out and can interact with anything applied on top. Over time that could make even something which is normally very sturdy, like dried nail polish, swell or crack. All you can do is try it and hope for the best.
Just snip a piece of dark grey vinyl or satin black car wrap, 6 in x 5 ft for $7.99, smallest available. $7.99 less expensive than replacing the radio as well as your time futzing around. Easily removes if you have to redo it. Premium vinyl car wrap lasts for 7 years on vehicles also used for outdoor signage, cast vinyl rated for 7 years, calendared rated for 3. Vinyl car wrap also used over bumpers so no need to worry about plasticizers. Lettering? Why bother, or just use nail set and punch a hole in the snip of vinyl and have the orange show through, signifying on/off. VViVid Dk Grey vinyl car wrap Amazon $7.99