tailgate window problem

this morning noticed tailgate wiper stopped working, then when I opened tailgate window dropped and would not come up.I removed panel and pushed it up,I tried recalibration to no avail,but i did manage to get the window up and down once or twice byholding dash switch but now nothing.The motor is running so i think it must be regulator problem.Is it difficult to fit my old motor if I buy just the regulator

Its a bit tricky to just replace cables

But only £15 against £70-80 for a full kit