Reload .vimrc in Vim without restart
:source ~/.vimrc
Run that from inside vim, that will apply your .vimrc
Alternately
:source $MYVIMRC
Here's one for posterity. Add the following to your .vimrc:
map <leader>vimrc :tabe ~/.vim/.vimrc<cr>
autocmd bufwritepost .vimrc source $MYVIMRC
The first line means you can open your vimrc from any vim buffer by typing your leader, then writing "vimrc." For example, my leader is set to comma, so if I'm in edit mode and I type ",vimrc" it opens my vimrc in a new tab.
The second line automatically sources the changes to your vimrc when you save and close it. It's magic.
:so %
if currently editing .vimrc