Correct way of doing it is to remove the alternator, then the support bracket complete with the tensioner , swap the tensioner then refit the bracket etc.

Some people may 'cheat' by undoing the tensioner off the bracket in situ, but there is little room to get an Allen key in there to undo the bolt.

Alternator comes out between chassis and subframe once os track rod end is undone.

Alternator lower mounting studs 15nm

Alternator nuts and top bolt 47nm

Track rod end 40nm

Alternator support bracket - block bolts 47nm

Tensioner retaining bolt 23nm

Tensioner to alternator support bracket bolt 55nm

Idler bolt 48nm

Crank pulley bolts 45nm + 120 degrees.

BEFORE you take the belt off draw a picture of it's routing and note how the tensioner sits in the bracket as if you get it in the wrong place you won't get the belt on