New tires are always harder to remove/install then used. The more used the easier, less material less stiff. Only had a few rope plugs fail on me, mainly from a non-round hole. Make sure you don't over ream the hole when using the reamer. When installing the plug is should be pretty hard to insert. Using vulcanizing cement helps lubricate while inserting but also helps seals once it vulcanizes. Requires riding after use for the vulcanizing to take place. I almost never cut down what is sticking out of the rope plug, instead I insert it till about only 1/4" sticks out.