On an EA82? The book isn't specific on if there is any way to do it without removing the timing belt covers. I'd certainly love to avoid that if at all possible.

Do you want the proper and exact method, or the quick and dirty?

 

Q&D: Pull out the rubber plugs on the center cover (one for left belt, one for right), loosen up the adjuster pivot bolt and then loosen the second bolt on the adjuster... the spring should take up any slack... then retighten the second bolt and tighten the pivot bolt. Replace the cover's rubber plugs.

 

Proper: Remove rubber plugs, remove outer covers, rotate engine to specified point (IIRC, cam sprocket lined up with its "timing" mark on rear cover), loosen adjuster pivot bolt, apply 10ft-lbs (IIRC) tensioning-torque to the cam sprocket, loosen the second bolt... retighten the second bolt, tighten the pivot bolt, remove the tool torquing the cam sprocket, and replace the covers and plugs.