Most are auto tension assy's, use a spanner or similar, depending on space, (Some have no space to use a normal spanner, and a extra thin one is needed,) usually a square end on the tensioner unit, fit spanner unit will move to the side, allowing belt to come off, Thats how it works on my VW, and a lot of others the same. failing that, if not tensioned by alternator, could be hex key fitting in middle, but usually be able to lever the unit to the side in some way. Once over belt off. refit same
SD, December 2011
