There are 3 things to consider if you plan to make a change like this.
1) The LSS and LSC are looking for either 4 or 8 ohm loads. Whatever you put in has to be matched to one of those loads. I don't know much about 10" speakers, so you'd need 2x8 ohm wired in parallel to get a 4 ohm load. I haven't seen a 10" with 16 ohm load, but I could be wrong.
2) The power rating of the speakers will need to handle half of the maximum power output of the amp. So, if it is the LSC, you'll need 10" speakers that can handle 50W each. The LSS would be 15W each, and that seems more reasonable.
3) You'll have to make or find a mounting adapter to convert the 12" diameter holes in the cabinet box to 10" holes.
The first 2 points might be why they do a 4x10 cabinet - that'd be easier to get the right load and power handling.
All said, it does sound like it can be done if you take the care to make sure you match things correctly. Probably tighten up the low end nicely.
Hope this helps. Please, correct me, anyone, if I am wrong or if there are things I am missing.