I would like to open the MBA, i don't have the screwdriver that fits this:
Is there a way to remove the screws without the 5 points pentalobe required?
The ideal solution would be to do this without damaging the screws.
You cannot safely remove it without the proper tool and the correct touch. You want to place the driver on the tangent to the case (the screws enter at an angle - not vertical compared to the keyboard plane.
iFixit.com and other places sell the pentalobe tool for less than $15 and it's money well spent to avoid needing to get Apple to replace the screws should you strip them.
I managed to do this with a 1.2mm flathead, it obviously doesn't have as much torque as a pentalobe driver, but it doesn't strip the heads if you're careful.
Also, this trick works, but you need the right pen (hard clear bic): http://www.youtube.com/watch?v=ONd7quApjGM