Place a 6 inch piece of timber on a solid floor (concrete or similar) with the end grain pointing upwards. This allows the wood to absorb just enough force to avoid damaging the hammer.
I never use the 3 part shellholder that comes with the hammer but a Lee one that normally fits in the reloading press for the particular cartridge.
Never attempt to remove the bullet with one hard strike but aim for three moderate ones. With practice I can unload a round in a few seconds.
I agree with Dr spin... i had been thumping away on various surfaces with limited sucsess until i discoverd hitting a lump of 4x2 on the grain works perfectly, i can hold it between my knees and they come away no problem. I use it when fine tuning seating depth ie knock them out slightly and reseat