Download from Fly Away

Can anobody help me :
I am NOT a computerexpert- but FSX is a wonderfull tool.I love flying (and have been so lucky to cross the Atlantic in a Concorde - in cocpit !)
I bought the fsx a month ago and should like to download futher aircrafts
from FlyAway.I did yesterday with the TigerMoth- no problem .
But I am stocked with any other models since .I bought the WinRAR program to unzip , but what to do then ?
Thank you in advance for any help - remember to give detailed instructions as I am not a computer freak.
regards
PEA, Denmark