Yes I've done it. It is like pushing a chain up hill, if that tells you anything. Follow the instructions, don't skip anything. I finally tied some 80# braid around the cables and pulled and pushed them through the shaft. Have plenty of room to spread out the trolling motor because you will damn near completely disassemble it. Don't drink too many beers while doing it. Have a friend help. Be sure to use all the new parts, even though the old ones look fine. And have a 6mm (?) hex key that has the roundish end on it. Don't quote me on the 6mm but whatever it is get one that has the rounded head.
And the best part is that I get to do it again sometime this week as my new 56UHD is on the way.
Good Luck. Send me a pm if you get in a jam.
Retired grass grower