Hey, was wondering, I just put some 33/12.50's on and would like to set my Speedo correctly, I know where the cable comes from the transmission, I have never fooled with a speedo cable before and was wondering is it simple to do and play with until I get it right or does it just cost a couple of dollars to have a mechanic to do it,Is it worth messing with?? what should I do, thanks!!

1990 LWB 3.0L With 33/12.50's K&N 251k Miles