2X4 against tire(do not hit the rim) and hit with big plastic "tire hammer" and
if they get them apart what is there to prevent this happening again?
when re-installing use plenty of anti-sieze or spray the hubs with a lot of white lithium grease before re-installing. And (your not going to like this) consider rotating tires maybe every other year or atleast pull the tires off and re-apply. (Might as well rotate if you pull them off) And try not to mix metals, alum with steel if at all possible. If that is the case. Be sure to check out the lug nut holes to make sure they are not "egg shaped".
And I knew nothing about this until reading your post and at same time was already on the phone with a guy that used to be a tire guy. I had no idea and don't really know if this will work or not. But he says it will. Sounds good, personally I would still get other opinions. This guy worked doing service calls on big truck tires for many years.