Two of my glow plugs test bad (with an ohmeter) and I have ordered the glow plug reamer. As soon as the reamer gets here, I want to do the job. However, I get conflicting advice with the search. One school of though says remove the hard (metal) fuel injector lines for easier access. Another school of though says drive the car hard and stop and unscrew a glow plug fast while everthing is still hot. Are these both equally accepted schools? Also, I read a couple of horror storries about having to drill glow plugs out of 603 heads. How likely is it that I will have trouble getting the glow plugs out? Should I soak them in penetrating oil the night prior?

TIA.