You will need to loosen it all off, just don't overdo it as you obviously don't want the mast flopping around like the proverbial drunken sailor but loose enough to allow you to get the mast centred correctly. If you try to tension the rig in the wrong order without loosening you'll probably end up with your mast bending in all the wrong ways.
"Do you think God gets stoned? I think so... Look at the platypus." Robin Williams.