Thrusters aren't too bad, I’ve replaced stern thrusters in the R25 and R29 with the R29 being far easier to access.
On the R29 I had to remove the stern gas tank which was not too bad then you just inchworm yourself in there to fight the two fasteners that hold the thruster motor to the transom.
To get them to begin to turn I used a cut down allen wrench as mentioned above but I had to put a 10 or so inch piece of plumbing pipe on the end for a cheater bat which helped immensely as i couldn’t get them to break loose just tugging on the allen wrench.
I also tried a cheater bar on the tool shown in the link and it made a crunching sound as it exploded, hence the advice to use an allen wrench for breaking the fasteners loose in the beginning.
First make sure the socket on the fastener is clean and hopefully not stripped ‘cause if it is or you strip it you’ll need to cut the head off and how to do that in that confined space would be quite the challenge. You’ll need a spinning ablative cutter for trimming the allen wrench down and use a good quality wrench, again, you really don’t want to strip out those fasteners.
Also, I used new fastiners in the install as the sockets on the originals showed signs of wear, I always try to think of the next guy ‘cause usually it’s still me. Needing two I bought four, two to use, one to lose, one spare.
As you undo the two fasteners you'll have to bump the thruster assemble away from the transom so there continues to be sufficient room for the tool that’s turning the fasteners.
Once they're loose and turning the difficulty isn’t turning the fasteners it’s changing sides with the wrench, getting it back in the fasiner. So after my R25 adventure I bought three wrenches having destroyed the first one and on the R29 it was break the fasteners loose with the allen wrench with the cheater bar on it, put two wrenches in place, five yanks on one wrench, five yanks on the other wrench, yank on the thruster, five yanks five yanks thruster yank etc.
Also, I built a little cradle for the thruster to take its weight off the fasteners while backing it and them out but if this causes the wrenches to not ratchet you’ll have to just let it dangle there during the removal and I don’t think this causes any harm. The cradle is handy on the install to keep things in line as they go together and the instructions I received with the new thruster actually advised to support the thruster if it’s mounted horizontally but I think this is likely due to the pounding on go more faster boats than our Rangers but Yes, I did leave it in place.
So I bought my new thruster at a place called Marine Warehouse in Alabama for $2,200 and $28 shipping to the west coast which was by far the best price i could find. I also found those ratcheting allen wrenches for $8 or so bucks which took the sting out of having to buy three but I forget where I got ‘em.