How can I take apart my OLd Mac Se or anyother mac Monitor apart so I can just have the case/Shell?
There is a distinction to be made between a CRT display (monitor) and Classic 68K (all-in-one compact Macs). A display contains a CRT and its power supply. A compact AIO contains a logic board and a power supply for the computer, and a power/analogue board for the accompanying CRT. However, neither CRT nor AIO should be opened unless you are experienced, or prepared to be careful and to read about where the danger (to you or to the computer) lies.
The compact AIOs from 128K to Colour Classic need a Torx-15 driver to open their cases. All but the CC need a driver with a long (at least 21cm or 8.25in) shaft. You will find some pointers about opening the cases here: http://home24.inet.tele.dk/ccadams/se/ram.html
Ignore the taradiddle about Allen keys. The driver needed is a Torx-15, and nothing but a Torx-15. The tools needed to open the cases of displays are not usually so specialized, and vary from one display to another.
as grannysmith says- you'll need a torx driver. If you are in the states Sears carries one that you can buy by itself for like $8. It has a nice long shank to reach the screws under the compact mac's "handle."
once you are inside the 128k through se/30 machine, you'll also need a no.1 phillips driver to take the analog board out. Your torx driver will be needed a couple more times to take parts of the chassis apart (if you need go that far) and to take the crt out (again, as needed). If you are messing with the CRT- look here:
That guide also mentions disassembly- though I'll mention a couple of extra things. After the torx screws come out, lay the mac screen down on a towel (on a table) and gently pry at the case parting line with a flat bladed screwdriver. Easy does it or you will gnaw up the plastic. Some folks buy and use a "case opener," but you can improvise one from a spring clamp (also at Sears) with the "teeth" folded out straight. The resulting duck billed spring clamp will fit in the parting line- and when you squeeze, force the halves apart.
If you are going to chuck the innards of the compact mac (like when you're making a macquarium, say), you might post a thread on the for sale forum and find a suitable home. You can usually find someone willing to take compact mac parts.