Is pretty easy. I had one off ebay sitting in my basement for a year (correct color and in good shape), and the only question in my mind was what the flexible 1" wide strap was coming from where it meets the bottom of the header panel area.. My suspicion that it is a point of attachment were verified when removing the old fender - actually both. Long story short (collided with a deer last week, denting the OTHER fender), the fenders are easily removed and those straps are supposed to have a welded bolt at the end. I drilled out what was left of the bolt they snapped off, and used my own bolt. Each fender has two bolts into the header panel, one down to the front of the wheel well via a strut, the bolts along the top, and the two inside the door jamb. The bolt sticking out of the flexible strap I mentioned goes through the wheel well and a nut is visible below and behind the headlight each side at the lowest point you can see 1/2" behind the header panel. As any 850 owner knows, the area behind the headlight and under the hood latch is just about impossible to get to on the passenger side, and somewhat better driver side once the battery is removed. BTW, if you have time and noticable dents in your fender, I highly recommend removing and carefully pressing out by hand, or possibly tapping carefully if of a smaller more creased variety, or replacement. After encounters with a trailer hitch on the right and the deer on the left I had to do something. Oh, yeah, this assumes you have removed your headlight moulding (unsnap), bumper cover (torx screws into top and bottom of the bumper, one hidden bolt to the fender under the car each end) and all the rivets along the wheel well. Volvo sells the black coated rivets for around .20.
Don '95 850T

In case you were wondering, the deer dents came out fairly well. The poor deer was not as fortunate.