Ha Le

If I understood correctly, you meant the control switches just assembled in the door yeah? (Like you operate it with your fingers, not some hidden place - which I don't believe so)

These one can be bought for $13 (single - like the passenger one), or $50~$60 (set of 4 - driver one) - but again these are prices from wrecker yard. But I saw couple of times on Gumtree for about 50% higher price.

Install would be even easier, just a pocket knife will do the job. Unplug the wiring and replace it.

Should be easy fix mate, cost per set of motor/regulator $41 (self-serve car wrecker) eBay much higher + shipping cost.

Replacing requires minimal skills, just some screws and there are plenty of video on internet

Source: done it myself, for the rear though but pretty much the same.