if superman our enemy how defeat him?

I would not want too, but if we had too, we would have to get a lot of cripton and surround him with it.

why he will be our enemy . he may be our friend.

i not want to. but if that is true, maybe we should have many cryptonite stone very much to make him weak

In the encyclopedia of superman(yes there is such a thing, my boyfriend actually owns it). It describes what Krypton is, chemically speaking. We would need to chemically make Kryptonite and figure out a way to encapsulate Superman in it.

Or we could just follow Superman Returns and stab him with Kryptonite, rendering him useless(at least for the moment) and hope that the radioactivity is enough to keep him at the bottom of the ocean.

As we've learned in the past though, even if Superman is temporarily overcome by an obstacle, he eventually returns to his proper self and wrecks house.