Hey Preacher,
Use two people (one on either side), pull the mattress back and fit the covers at the head-end, then push the mattress back and tuck in the bottom. We did replace the OSB with 1/2" baltic birch plywood to prevent splinters and make sliding easier. About an hour job. We also readjusted the gas shocks to provide more leverage to lift our eurospring mattress. Hope this helps.
Mark