Windows Key(logo)/Start if you're using Windows, then type in Run and use that. Once Run is open, type in %appdata%. Once there you'll be in a roaming folder, so just double click ".minecraft" and you'll see the bin folder.
Or assuming you have the new launcher, but i mean come one who still uses the old one? haha
Anyway once you are about to log in, Click options and click that blue link that is pointing towards the location where minecraft is on your disk.
-Open up the start menu
-Type in "run"
-In the search bar that comes up, after clicking the run program, type "%appdata%" and click "OK"
-Find the .Minecraft folder, it should be on the top of the list. Click it.