The reel comes with 2 spools, take the spare spool and wind the braid on as tight as you can, ALL THE BRAID, then when the braid is all loaded connect the braid to mono (2 biminis) and start putting on the mono till the spool is full (mono not so tight).
Now take the spool off
Put the empty spool on, tie the mono onto the spool and simply transfer from the one spool to the other
ENJOY, I recently bought the 2500 for my very light fishing, haven't used it yet, but soon ...