To go from 4x100 to 4x114 you are changing the spacing between each of the bolt holes. All four holes will need to be redrilled with precision and chamfered / finished, etc.
You need a quality machine shop that can place the wheel(s) in some sort of jig and drill and finish the new holes properly. If the wheel wasn’t designed to have a “universal” (4x100 & 4x114.3) drilling from the start, this may result in unnecessarily high stress levels at the center of the wheel because you are removing material that was not designed to be removed.
Not trying to rain on your parade but unless those wheels really mean a lot to you it may be more trouble than it is worth. It may be worthwhile selling them and then buying another set that actually fits your car properly.