Depends how bad they are...
I had a similar problem with my 2004 XLT. Understand this is a common problem with most vehicles with leather upholstery, the first area to go is usually the 'bolster' or raised side of the seat squab that you generally sit on and compress as you wriggle onto the seat getting in and out.
This damage is almost inevitable and show on almost every vehicle I have seen with leather after a few years. On the explorer seats, interestingly several of the panels are not real leather, they are very good but fake PVC leather and they seem to have stood up better on mine than the actual leather...
I had a very experienced auto upholsterer check mine as I wanted to make sure it wasnt going to get any worse. He told me if the wear and cracking is light, and it is scuffing rather than cracking, it can be filled and colourmatched by a good auto upholstery place so that the repair is virtually unnoticable.
If like mine it was more severe to the point where the leather fibres have started to separate, then they can't really be filled and replacing the panel with a new piece of matching leather is needed - expensive and not really a DIY job.
The best solution - and this is now too late of course if the wear is already evident, is to keep the leather well cleaned and maintained using a leather conditioner. A car seat is about one of the worst environments for a natural material like leather, particularly in extreme climates.
I doubt my post helps much, but good luck, I would take it in to a good specialist auto upholsterer and let them have a go at it.
Take a look at this site, it will probably not be local for you but has some good info and links.
http://www.leatherhelp.co.nz/leather-repair.htm
Neil.