I don't think you'd really need to clear the memory or anything,and yes,the fifa .sav is on every card(it has to have a .sav in it at all to work(or something...)
There should be a screw under the NEO sticker on the back,if you absolutely feel the need to get in there.(Thanks Cory....

)
Slide the top part of the case down(carefully),then lift it.
Just be careful,but you should be able to lift the entire board out of the case to examine.It's pretty durable(if you got the nutz to get in there,you should be o.k.,y'know?).
I have done so with a couple,and they work fine,but one version I have (the production model)has the battery"glued"(I don't know,really)in.
But I really think the software(NEO2Manager)and the menu versions can"clear out"anything you need.

EDIT:I may have implied by my post that I've got the "nutz".I dont.I was in there out of necessity(testing and whatnot,hehe),and was terrified the whole time.
But it worked out O.K.
EDITEDIT:My explanations are from experience with the SD version,and there may be physical differences I am unaware of.
I don't plan on buying a TF card,anyway.(The more flush front edge sounds appealing,though.Maybe they'll make an SD version that slides in the side.)