the space bar not working right

Having to push hard on a key is probably a defective keyboard. You could try popping off the key cover and blow it out.

To remove the keycap from the keyboard place use your finger nail under one of the corners of the key and gently pry the keycap up and away from the laptop until you hear a snap.

The same keyboard fits the Vg-573, or so it's said.See if this looks like it will work with your 552:

http://www.myfixguide.com/manual/acer-aspire-v5-573g-disassembly/

Down in the comments a poster said this:"Look at the 2nd to last picture, the closeup of the top half of the case after the motherboard is removed. The black plastic has a sticky backing, peel off the top and left side where it is stuck to the plastic chassis starting at the two foil tape pieces at the top. Once that’s peeled back you should have access to all the plastic melt rivets that hold the metal tray to the chassis. I snipped them off using some flat head pliers, and you won’t need to snip all of them – there’s some that connect the metal tray to little brackets along the left and right sides. You only need to snip the ones holding the metal tray onto the plastic chassis. Once you have all the rivets broken you can pull off the metal tray and then remove/reinstall the keyboard. I then used electrical tape and some finesse to reassemble the top half and secure the metal tray to it as best as possible. The motherboard screws and hinge screws hold the assembly and black plastic layers in place, but the tape helped hold the keyboard in place at the edges. It’s not 100% but very very close and much better that paying for the $150+ full top tray assembly. I hope this helps!"