Please show me where there is a seal on the PULLEY.I would only do that as a last resort, you risk ruining the seal, there ia a tool to put the pulley back on with.
These keyless pulleys are a shrink to fit type. The PULLEY should be heated up to around 150* to install. You heat them up and use the install tool to replace them. Have done this many times. If not heated they will bind up before seating all the way on the shaft. They dont have to be heated to remove. They make a removal tool for that.