Most 1/16 tanks can be easily opened. Some are just a few screws (HLPzr III/Stug) and some are very involved (HL Tiger I). It may be comtingent on what you do with your tank. I do fast paced IR tank battle so I need a very secure hull system. IF you don't battle you may just get away with gravity or a magnetic retaining system. I rolled my newest Sherman yesterday at Bretts in PA and it came back onto its tracks and I kept battling. No harm or damage done. It is a stock Tamiya M4 and uses two side friction latches to hold the upper to the lower. Just spread the hull outward to open and push doen to reinstall. Some guys use magnets. Most Tamiya FO kits use a very secure built in screw in the rear and have a interlocking lip in the front of the tank (Panther, KT, JP, KVs ...etc) On my Tam-Long tanks Pzr III & Stugs is use one screw in the front that goes thru the lower hull into the upper. The rear two screws were eliminated and replaced with long metal studs with lock into the upper hull holes where the two rear screws used to be. It is very secure and can be opened in under 30 seconds. What kind of tank do you need help on?