I just did the same, cut the bolt with the angle grinder, clearance was close. I cut part way through the bolt turned it and cut the other half. Use an old license plate to protect your distributor wiring.
just pull all the screws holding the dash bezels over your gauges and pull the remaining screws from the entire dash "pad" pull it off, the vent grills are attached to this. run your fan on high then vacuum up whats left...