If you can differentiate a spanner and a screwdriver, then it is DIY-able.
Problem is to see whether it is faulty or not. You can the spare part from AB or chopshop.
Step/Procedure.
1. Open rear boot.
2. Remove hard cover on the right side of boot (driver side). You might have to remove some clips to do it.
3. Use a touch light and locate the retaining bolts. You might have to use a torq allen key (six sided star) to remove the bolts.
4. Remove connector to the actuator.
5. Swap the actuator and check it.
6. If all check OK, re-assemble in reverse order.