No, it's not that easy. Well, maybe if you have the right tools. And that's just the beginning. Here's what you'll have to do.
Since the oil level is just about coming out of the case, you're better off dropping the Trans pan and servicing the unit with a new filter and fresh ATF. The other alternative is to get a thin enough plastic hose to snake down the dip stick tube, and suck fluid out that way. Pull enough out so when you do pull the tube, fluid won't pour out all over the place.
The tool you'll need is a long extension 3/8" and a (either/or) 13mm/1/2" swivel socket. Now that you're under the car, look at the bell housing and block where both meet. Do you see the tub's brace bolted to the engine? Remove that bolt with your extension set-up. Once you have the bolt out, have someone up top, try to pull the tube up enough, so you at the bottom, can swap-out the rubber grommet. That tube will be about 3" deep inside the case. It might be easier to have the Trans pan off, so you can see how much more you have to yank on the tube. Be careful about the tube's brace. You'll bend it a little trying to loop-hole this. I doubt you'll hurt the integrity if you just be patient with all the swaying to maneuver the tube up enough and out of the way. All you need is enough gap to swap gormmets.
Before you do all this, just make sure that tube grommet area is oil free and clean. Spray contact cleaner all around the old grommet, and sanitize the area. The last thing you want is dirt going into the Trans. And also, grit in between that new gormmet to cause a fresh leak. It can be done.
