£2800 sounds a touch steep. I could be wrong but I'm sure the mechatronics can be replaced in situ like a traditional slush box auto?
I'm sure the mecha pack was about £1500 from VW, but that might have been years ago
Given the potential cost of replacing bits and your unDIYness, you might be better off with a used box from a low mileage car. 6 hour book time to drop and refit a box, so the labour for that might work out cheaper than fiddling with the existing box.
That's why I did that with my manual. Rather than buggering about rebuidling the crusty old worn out original one, I scored a MK6 GTI box for £250 instead from a 45K car and it was perfect
If you like the car, the investment is probably worth it rather than starting over, as that's faff plus the risk of potentially buying a lemon.