My outhaul was overridden with a sail tie when I bought the boat. Cable locked up and line too short to reach the cleat on the boom. I tore into it last weekend and found the job not too difficult. I suspended the boom off of the main halyard and used the vang and halyard to find position and balance. Topping lift removed of course. Only tricky part was knowing where and how hard to hammer on the end caps to drive them out of the boom. Gentle, as there are some thin sections. Only corrosion solvent I had on board was Deoxit (works wonders on electrical contact corrosion, so...) and this did the trick.
Looking at the photos you can see the cheap hardware leaves an upgrade opportunity. I reassembled without upgrading blocks, but if any more trouble, I'll know what to do.
Work from the front, but you will need to pull the aft end cap and remove the sheave to allow the cable to be pulled into the boom. I just tied a line on the cable as a tracer.
My boat had 5/16 line installed, but the manual calls for 1/4. 1/4 seems to work smoothly now and plenty stiff. Only regret is I chose not to replace the reef line at the same time, but the 100° Houston heat was clouding my judgement. /Ed
