Thats what I plan on doing. The original tires are pretty expensive compared to most aftermarket tires (my opinion). So, when we need to replace ours, I will do some shopping, and ask a ton of questions before I drop coin on any tire.
Take it easy.

 

Don't know if it is of any help, due to the fact the company (Discount Tire) is American, but maybe a local (or big chain) shop in you area can perform the same proceedure. When I was trail running with fellows from the NAXJA in Northern Michigan (the UPee). They have this company "sip" their mud tires for winter running. (Info site is www.discounttire.com/dtcs/tireSiping.dos) I have access to this company (living right on the border) and have bought tires from them (great to deal with) but have yet to inquire about the proceedure or cost.

 

I ran 2 winters on 35" ProComp Xtreme M/T and they were alright, awesome in deep snow and just OK on ice and hardpack. This year I have 35" GoodYear Duratracs. The Duratracs so far seem to be much better then the ProComps and def better then the stock crap.. Duratracs can be studded...
I purchase all my tires from the US from tirepackages.com because our local tire shops refuse to come even close to the US price. Don't get me wrong here, I am all for shopping Canadian, but $1000 difference for the same set of tires and rims is a little hard to overlook...