Air Conditioning - Preparing for bigger in-wall air conditioning unit

I'm going for DIY. I recently had a contractor do a brick replacement on my brick 2 story. In that the In-Wall AC was some 40 yrs old and was ineffecient we had got recommendations that suggested our new unit, after our extensive search, would be bigger than the old. We bought the new 24k BTU units to replace the 14k unit and had the brickies form the outside brick to the new dimension. We also got a tin smith to build a new sleeve for the new unit. Now for the interior work. The contractor was going to do us a favor and remove the old sleeve and do the interior work necessary to put in the new unit but got busy on other projects. This is a rental unit and our tenants are starting to feel it upstairs. So a favor turned into DIY. We needed to change the plug from 110 to 240V, done. Now for the rest...What I THINK I need to do.

1) Remove dry wall to studs and expose old sleeve support & outlet.
2) drag contractor back if interior block wall is not trimmed!
3) have contractor grout smooth opening & check dimension against sleeve.
4) Adjust, remove & build-in lateral studs for new interior framing
5) Install new sleeve with slight tilt to outside, caulking outside flange lip to new brick with construction grade caulk. Ex. liquid nails.
6) fasten new sleeve to interior framing (sheet metal screws or liquid nails )
7) Allow caulk to set while adjusting outlet offset from edge of new AC dimension (What is this dimension?)
8)Install AC into new sleeve. Check tilt.
9) Close up wall

Sounds like you got it all. For that new 2 ton You did run all new bigger 220V wire