Acrylic is very breakable, it's supposed to be 10 times stronger than glass but how strong is that? Polycarbonate is much stronger and is really hard to break but is more expensive.
To remove a sash window first run a stanley knife around where the staff bead meets the frame.
Then using a small prybar or old chisel prise the staff bead off starting in the middle.
The lower sash will now be free and you can take the sash cords off, usually 3 or 4 nails and its easier if...