The only other hive I have is also new and only has about 3 Frames of brood. I think i will just try to find a Replacement Queen, so how would i go about requeening them when they have a queen now.
First off, you need to be 100% certain the queen is a dud. Sometimes they take a lil while to get going. M.B. can prob direct you better on this.
If you have to replace the queen, you will need to go in and catch the dud queen and remove her/kill her. I would do this a day or two before introducing the new, caged queen.
Btw, you have checked with the supplier you got them from right? To see if they would give you a new queen.
The first thing I would do is see how the bees respond to your new queen. Are they biting at her, acting aggressively towards her, or are they trying to tend to her?
You will want to place her in the cage inside the hive for at least a couple of days to allow the bees to accept her. After say 3-4 days you could remove the plug and let the bees eat the candy out of the plugged end and release her.