I have an iPhone 4s. I need to update but I don't have enough space. Any ideas?

I was thinking save to sim then reset phone. Them update. But how would I get all my stuff back?

Updated using iTunes on your computer. That way the update gets downloaded to your computer, you can opt to BACKUP your phone (which you should), and then it will not matter that you don't have enough room on the phone, because you don't first have to download the OS file to the phone, so it can then unpack and then install itself.

This is the best way to do all your upgrades, because you get a total back up and if anything goes wrong with the update (and it happens from time to time), you don't lose anything.

Do it through iTunes on a computer. You can't save to the SIM. Its not a memory card. Of course do a backup before hand so you would have something to restore to afterwards.