I recently purchased a 92 300SE,w140,without the remote
control s...,there are a couple for sale very inexpensive on ebay
(part 140076003),I dont know if the procedure for programming
in the owners manual is correct or I will waste my money buying
and old remote(looks the same with the one displayed in the
owners manual),ANY ADVICE?

They are not user programmable, they can be re-synced by following the proceedure in the manual. The first version was a rather big remote with no way of attaching to your keychain. The second version is smaller with a key loop. Be wary of those E -bay deals, I got my last one at the dealer for $125 with a key.