Hi there. It's a fairly easy DIY job, as it'll be the drivers linkage that has siezed. Take the wipers off and the scuttle panel, then you'll be able to see the linkages. Spray some WD40 and try them on, make a note of the resting position, or take a photo for later. I sprayed mine for a few days to help strip it down, there's a circlip you've got to take out and then it should come apart. Use plenty of copper grease once freed and re-assemble.