Steering column help

Hello everyone, lookin for some help, i started replacing my steering coupler and the internals because i ve had slop in my steering for years, installed the coupler and parts on the steering column and tried to reinstall, lined up the main splines on the coupler and power steering box, still a major fight to get on, ended up taking coupler off the column , installed it on the gear first with help of a piece of wood and hammer through the hole under the dash, then tried installing it that way, another p.i.t.a.ended up collapsing my column now. So now i think i have to take the whole column apart and fix it. I watched some vids that made everything look so easy, not the case here. Anyone have any tricks or advice for once i get the column ready again, and anyone know what shaft measurement should be from end to end? Pls and thank you