I don't know about the software, but generally speaking conversions are really easy.
Think of "basic" grain this way:
1 pound grain = .75 pound LME = .6 pound DME
All specialty grains would remain.
So, if you have a recipe like this to start with:
4 pounds DME
1 pound crystal 60L
Your new recipe would be:
7 pounds Two-row
1 pound crystal 60L.
In extract recipes using dark LME, that conversion isn't as good because the darker extracts have other grains already in them, like crystal malt.
The other thing that might change is your hopping rates, particularly if you were doing less than a 5 gallon boil before. The hops utilization would change, so you may need to adjust the hopping.
Almost all recipes would be fine with a single infusion mash.