Look for the icon on the toolbar that looks like an arrow pointing into lines (of code) -- if it's not there, then see my second paragraph below. The Debug menu may also have these commands, depending on your profile. However, the profile that you choose will change the actual shortcut used for the keys. To check what your keyboard profile is, choose "Tools\Options," "Show All Settings" (in the lower-left corner of the resulting dialog), and then go to the "Environment\Keyboard" settings. On my machine, I have this set to "Visual Basic 6" and thus the keystrokes are F8 and shift-F8 for those commands.
Also, if there are commands that you want to have on your toolbar but are (for whatever reason) missing, you can go to "Tools\Customize," click the "Commands" tab, and drag commands from the right-hand pane to the toolbar you want to change. You'll find the commands you're looking for by clicking "Debug" in the left-hand pane and scrolling down to the bottom in the resulting right-hand pane.
Hope this helps!
--Matt--*