I mean the pulley rotates, and you need to hold it still with something in order to screw/unscrew bolts. I have found out, it is possible to unscrew bolts by using a second ratchet/breaker bar to hold on to another bolt in clockwise (tightening) direction. Although this tightens the second bolt to some extent at the same time you unscrew first bolt, if you repeatedly loosen all bolts in this way, all bolts will come loose eventually because this method does not tighten bolt more than it loosen bolt, as friction plays a part.
Now my question is, how do you tighten all bolts? You cannot do the reverse as this method loosen more than it tightens.