Give it a rinse with fabric softner, and spin the water out of it then gently pin it out and block it like a sweater. I have done smaller pieces this way and it works. Take it to your church or school where there are work tables and get a friend to help you so you can square it up across the diagonals etc. If you have clotheslines you can pin it upto dry. Oh I forgot, if you happen to have old curtain stretchers that would work too. Also I have used the folding cutting boards that are made from cardboard, but I would put a sheet or something under it. You might need two of them. Good luck