yes you have to ruin the seal to get it off. The trick is not putting a mark on any of the surfaces while doing so. There are a million ways to do it, you will just have to figure out your style.
The worst thing you can do while removing a seal is scratching/marking the crankshaft or camshaft.
The worst thing you can do while removing a seal is scratching/marking the crankshaft or camshaft.