Just moved my motor into the boot followed the guides out there on forums, stripping the shelf out was straightforward and removing the side support rail, that needs a good tug to get it over the hump at the rear end of it. Managed to get the top of the plastic motor housing off using a long bar as a lever to break the tape sealing the top to the bottom half of the casing. Motor was still held tight by cable ties but a good pull upwards snapped them and the motor was free and pulled back into the boot. Another hefty pull on the lower casing snapped the cable tie holding that and it was pulled out. Secured the motor to its new position behind the boot carpet and secured to the bracket under there with cable ties. Drilled a couple of 10mm holes in the plastic side rail and slotted them to feed the wires and pipes through in a tidy fashion. Put it all back together and did have trouble refitting the shelf securing clips, you have to reach over and under the sides to get the clips to slot in their holes, rear ones easier than front ones, once you have them in the right orientation they snap in with a click. Front ones are best replaced working from in side the car and reaching over and under the roll bars. Once you have moved and secured the motor in its new place probably best to give it a test, just pop a suitable sized socket in the central microswithch to close it as the shelf is out and test the roof operates ok down and up. If all is ok pop all the parts and shelf back in. Spent all day doing it, hardesat part is getting the motor casing top off, mine was not the original motor and the tape used to secure the lid was not as strong as factory used tape. People do have problems getting original tape to let go by all accounts I have read on the web.
There was nothing wrong with my motor and no evidence of water in its well, had previously checked the drain which can be accessed through the small removable panel in the rear wheel arch. Once this is removed you can look inside and see the rubber drain valve, give it a poke with your finger and check its free, its just a small rubber flap at the end of the drain pipe.
If yours has filled with water and rusted the motor then from what I have seen a good clean and spray with something like WD 40 or a soak in diesel will free it up if its really bad. People seem to be able to revive the motors with a bit of work.
But if you're in South Wales he's up North 