Ok, I am still in the process of rebuilding my jack, an older Barker Super Jack and taking of the 'cover' just exposes all the gearing, limit switch assembly and motor. But removing the 2 allen screws from the collar mounting point to the jack would be much easier even with resync'ing the switches.
The manual for mine can be found here
. It actually shows a diagram with the power head removed to use the hand crank.
Also the newer models as well with parts list can be found here too. This is great information to have with the TT 'just in case'.
Also, and I can't stress this enough, please, please remove the allen screws and lubricate them with an appropriate material once a year. The screws are made from a hard steel where the powerhead is not steel. This causes a galvanic reaction otherwise known as corrosion. Mine were corroded and had to be drilled out, now I have to replace the lower part of the casing to provide a good ground to the jack and chassis. This would also be a good time to put a little grease on the gearing under the afore mentioned 'cover'. It'll take longer to get the toolbox out then to lube this thing up, but it'll save you in the long run.
By the way, while $300.00 is a bit for a new jack, they at least have cool little lights on them so you can see what you paid for!