Split the cases. I did it for the first time here recently and its super easy. Get a manual, take your time, follow it step by step and be done with it. After spliting mine and knowing now how the seal sits, I don't see how the way you put your seal in would work very well. It has to sit properly in the grooves and you could of easily messed up the new seal pushing it in. You could likley never have another problem with it but its all about peace of mind.