Knuck, just open it & stop halfway, no problem. I do mine every couple of weeks w/ the 303 and I make sure I get the seal at the top, where the 2 halves meet. While the top cover is up/open, flipper door up, look down inside for any fluid leaks, leaves, etc... Check your top pad and the Hyd. lines and make sure that they are not twisted or rubbing the paint anywhere. One of mine was wrapped around the stop point, rubbing on a sharp metal bracket edge, lucky I caught it in time. Do a search and you'll find all kinds of info on zip tie-ing off the lines, paint rubs, etc.. Tips & Tricks section is also good.
Here's another good thread on weatherstripping;
My 05 SSR truck bed water leak solution
Good luck!