Taking off the top.
To access behind the control panel, remove the 2 screws on top of the control panel and lift off the cover. To remove the whole top from the washer, remove the 2 screws on each side of the front of the machine toward the bottom, where the profile of the front panel changes. Pull the bottom of the front panel out and up so the top "hinges" and disengages the hooks at the top. Then remove the 2 bolts from the underside of the top (one on each side) and the top will swing up, it is hinged from the back. You should do this near a wall so the top of the washer can rest against the wall. Also, you should open the lid or tape it shut to prevent it from opening as you lift the top and banging into the control knob.
Might the problem have something to do with the pressure tube? Has the washer been used with hard water? Mineral deposits can eventually clog some components like the pressure tube. As an example, a clogged injector is very common and results in a leak from the left rear corner of the washer when it is filling and spray-rinsing. The injector is a $15.00 kit and is replaceable when the top is opened up. It might be a good idea to replace it while the top is open.
Good luck,
Dave