2015 V model 3 with 256k, needs HG now. Son has 2012 CT200h 175k.

welcome!
please keep us updated with pics if possible, all the best!

 

There's some head gasket replated links in my signature. Also last link is the full engine section from the repair manual. (on a phone turn it landscape to signatures).

Do be sure to clean the EGR system while you're at it, including the intake manifold (has EGR passages).

I'd recommend to get the Toyota gasket kit (includes new head gasket, a revised one), and new head bolts (existing bolts can be reused if within specs, but to play it safe). Attachment has part no's for both these, and the revised pistons/rings, less prone to oil consumption, if it's a concern as well.

 

Head gasket jobs on these hybrids are a little more complicated than a 74 Celica. Aluminum engines are prone to warping, access is tight and inverters, two cooling systems and an electric ac compressor add interest. Timing is often a stumbling block that has forced rework by diy'ers in the past. Some wish to replace water pumps and the thermostat while they are in there. Do your homework.