Since I don't have a Dremel, I opened up my holes (and I mean ALL my holes, if you open the top limber holes and leave the bottom ones as it will look silly) using just a hand drill and an X-acto. If you are careful and patient this will work. Just remember some things: 1.) each hole has to be bevelled (the kit's hull is approx 1 millimeter thick, it's a 1/72 kit, so just opening the holes would give you the scale equivalent of a 72 mm. thickness, which would be more appropriate for armor plating -- and you face a similar problem if you want to show any of the torpedo doors open, you would need to bevel the sides there too). 2.) When using the X-acto, wear a heavy work glove to hold the hull in your left hand (assuming your a rightie), as sooner or later your blade will slip and go skidding off in God knows what direction, you can really hurt yourself). 3.) You'll minimize the risk of doing this if you change blades frequently. 4.) sooner or later you'll screw up a hole. Just use Squadron Shop Green Stuff to fix your booboos. 5.) Even if youre results are less than 100% perfect, you'll be amazed how better they look once you paint your hull. 6.) Figure on this taking a month - six weeks. By the way, Yankee Modelworks makes a resin upper pressure hull with all the piping on top. If you can afford it, this is a lot easier than scratchbuilding all that stuff (the fit isn't too great, so make sure that the two holes for the periscopes are on the centerline of your boat). Good luck!