C200 windscreen wiper problem

My wife came back today with one thing, her C200's windscreen wiper got stuck to the windscreen's trim, passenger side. Searching on the net and found a similar problem here:

http://forums.mercedesclub.org.uk/showthread.php?t=42678

Will try the following DIY, else .. Mill.Merz I should go! :)

http://202tech.mkosonen.com/howto/wiper.html

Update 1: Opened up the bonet, disassembled the wiper assembly, cleaned up everything inside .. no juice .. WD40 couldn't help either.

Update 2: Went to Hakitrade/Puchong and got myself the wiper assembly minus the motor.

Update 3: DIY aborted, I couldn't fit the motor to the arm assembly that I bought second from Hakitrade. I need to go back and get the one that is compatible.. it seems that though both having the same part number, mine is the newer one and has six holes instead of three..

Update 4: OK, got a replacement .. but I will not go to Hakitrade/Puchong anymore. They overcharged me, went to Kemuning one and his younger brother charged RM120 less than the one at Puchong. Put back everything together in less than 30 minutes. Hopefully won't break again..

Update 5: When I was at Hakitrade/Kemuning, the assistant mishandle the wiper assembly and it didn't work as what it should.. totally the opposite .. but the boss fixed it in no time, he disassembled the body.. reposition the inside gears and all went well.. so, probably if you've the same problem .. open it up and try reposition the gears inside the body before you getting a replacement.