If I understand you correctly: You have two Sims - SimA and SimB. SimA lives in Apt 1 and SimB lives in Apt 2. You want them to swap Apartments (Apartments = Lots). You want SimA to move to Apt 2 and SimB to move to Apt 1. These are the only Sims in each household.
This is doable from Household management.
Move SimB into SimA's Household.
Since they're the only Sim in that Household their funds will go with them.
Now, move SimA over to the empty Household formerly occupied by SimB.
SimA will now be in SimB's Household and will "Inherit" SimB's funds.
You can adjust the funds to your liking.
SimA and SimB have now swapped Apartments (Lots).
You can adjust Household names in Household management.
Be aware that this may affect collections. Collections are tied to Households.
