MOH dress length trim -- can I diy it?

Hi! my sisters wedding is in a month, I got my dress in the mail but need to cut off no joke 4 feet from the bottom. that being said, I have room for error, and was thinking of trying to do it myself with a bit of the length at the bottom and if it works out then full send and do the rest. Ive sewn things before by hand, but basically just holes in stuff. I know thats way different, but if I just get the instruction/ right directions and I take my time I can do whatever. so im down for a challenge! but also more so open to the simplest ways for me to do this LOL. love my sister but im only 25 and I really dont have the money to spend on tailoring the dress now too considering it was already 200$ which is already my spending money for the month 😅 need me a nonna rn (also dress is satin)