Before starting with this conversion it's best to finalize the base because it's easier to pose your figure against its base than to try to fit the figure on a completed base.
Below I've placed images of the base I intend to use.
When you're happy with the base take the legs and remove the flash.
When you're happy with the result carefully slice the legs in half around where the knee joints sit.
The next step is a little trickier. Cut the toes off of the kneeling leg and shave a grove in the forward leg. The grove will help with the thigh position later.
Drill a hole into each half of the upper legs and glue a pin in one side. The other half can then be pushed into position, giving you a free range of motion to spin them around.
When you have the legs pinned loosely together have a jiggle with them and find a pose that you're happy with. If need be you can position them against the forward leg to help.
When you're satisfied with the final alignment glue them together.
As it dries you'll notice that the skirt isn't hanging correctly, this can be fixed later with some green stuff so take a file to it and remove the detail that is jutting out.
The next stage is to pin the lower legs. Glue the pin in one half as before, find the desired pose and glue them together.
That's all there is to it, a drastic change for little effort.
I hope you enjoy this and put it to good use, see you next time.