Question: What is the best way to go about replacing a Fairing (generally used for wing to fuselage joints) on a VMAR model?

Answer: Actually it is not difficult if you go about it the right way. Please review the entire process listed below before actually doing anything.  

The key to this process is to NOT remove the entire old fairing off the model. If you take the old fairing entirely off the model you run the risk of damaging the covering AND will have a more difficult time aligning the new fairing into position.

1) First of all do NOT totally remove the old fairing!  We don't want to take a chance on spoiling the covering so we are going to leave the portion of the old fairing in place that currently is bonded to the covering.

2) Instead of removing the old fairing, carefully clean it all off with Fantastic and paper towels. This will remove all oil, dirt and grime. Clean the fairing and surrounding fuselage area twice.

3) Use Pacer (the ZAP people) RC56 Canopy Glue or Pacer DAP-A-GOO to carefully bond any loose spots of the old fairing back into place on the fuselage. If you've had a crash carefully retrieve and reuse as much of the fairing as possible. Ideally you want the fairing contact area firmly bonded to the fuselage. Will CA work... yes but be careful to avoid "clorosis" which leaves a white powder like residue... use Pacer Poly Zap or Plasti Zap to reduce clorosis effects. Best of all is the Canopy Glue.  

3) Now take a new SHARP #11 Xacto blade and carefully cut the fairing about 1/4" offset from the fuselage. We want to leave the "stub" of the old fairing in place.  

4) Now inspect the remainder of the old fairing and make sure that it is bonded to the fuselage... you can work from "inside" the exposed portion of old fairing if you have to.

5) Carefully trial fit the new fairing on top of the remains of the old fairing stub. You should get a nearly perfect fit particularly if the fairings have simulated 3D rivets. The simulated rivets will key exactly into the new fairing rivets.

6) After trial fitting the new fairing, use Pacer RC56 Canopy glue to carefully bond it into place. Clean up any excess adhesive before it cures. Check several times in case adhesive oozes out. Use low tack masking tape to hold the new fairing in place until the RC56 has thoroughly dried.

That's it!