Retiring but have questions on Ficus

My 1st post and it's on Ficus -

I am being forced to turn my Bonsai and pre-Bonsai over to non-Bonsai persons due to health reasons. I have lovely ficus that has been kept strictly indoors since I bought it from a Bonsai nursery about 3 years ago as well as another that I've kept indoors as well from one of those pathetic little "bonsia" you get at Home Depot every fall ( looks pretty good now though).

I want to repot the good one into a newer but very marginally smaller pot (better color) and freshen up the soil a little. I want to repot the Home Depot one to put a better mix of soil into it - it is way too heavy on clay and needs more sand and soil. Being raised indoors at all times, when should I do this?

Thanks,

Short-timer

whenever you feel like it.