Well, I am really handy with aquarium sealant and a razor blade.
There are a few ways to do it. You can use an internal or external filter just set up a land area by siliconing a piece of glass or acrylic as a divider, fill it with gravel and soil, plant, and be done... or you can do something more advanced.
What i did with mine was silicone a piece of acrylic across, but it ends about half an inch above the bottom of the tank, allowing water to pass. I then built a waterfall feature using a pump and some rocks(make sure you have an unsealed but secure piece you can remove to unclog the pump if necessary), put together with silicone. The waterfall drains into a stream I built out of a piece of open-topped rain gutter shaped to fit with a set of heavy shears and siliconed in place to form a seal around the waterfall, leading to the water section. This way, you set up a complete current. The land section is then filled to just below the planned waterline with biologically active planting gravel (used by advanced fish-keepers). Over that, I put a layer of terrarium soil (pick your favorite brand of finely ground coconut fiber) mixed with moss. It stays moist via capillary action. I then plant this (Pothos. Lots of Pothos), and put moss and pieces of driftwood where there are no plants.
The water side should have a log , rock, or cork bark protruding out of it to let the frogs move between areas. Use either river rock or sand as a substrate, plant it well (i plant aquatic bulbs), and maybe break a clay flower pot to provide an underwater cave or two. You end up with a nice display tank.