I use a 2 ton press usually on all the engines I build, on the 120cc stroker I only froze and heated to install the bearing and crank.
Im building 2 kx65s into 82cc with new cranks, bearing, and the athena 82cc big bore kit. Just spent 1600 in parts and dont want to stress these new cranks. Theres an adapter I bought for c clipped primary shiz like the kx uses.