How can I change our outswing door to an inswing?

Rarely... without changing the entire frame... and taking care of any issues presented with weather if this is an external door as the threshold and frame will now be exposed to the weather.

As smoothy stated you will have a lot of problems.

The correct way would be to get an exterior jamb that is set for in swing. If a steel door the door will swing in opposite direction. When standing on the outside if hinges are on the left, after change hinges will be on the right.

If interior wood door you will have to plug old hinge and striker locations and relocate the door stop.

Chuck

Interior or exterior? For interior, the easiest way is to just buy a new door set. Exterior requires a bit more attention as you have brick molding, thresholds etc. If this is an outswing exterior door, it is a bit unsafe with exterior hinges as burglars can knock out the pins and jimmy the whole door out.