you can tighten your cog and lockring without any new tools if you just need to do it this once. use the rotafix method, which involves no tools, just look it up on youtube or something. anf then to tighten your lockring, not recomended but can be done safely, use a flat head screwdriver and a hammer just tapping the notches until it's tight enough.

but if you plan on doing this more than once i recommend getting a chainwhip and lockring tool.