Dollieh Sanctuary

Here's how I reduced an SD wig to a MSD wig. I don't have pictures of the process, only the end product (and my pictures aren't so great - sorry, photography isn't my gift.).
I put the wig on inside out on the doll's head and pinned out the excess along the back/ side seams. Then I carefully cut up the back/side seams from the inside. I made sure to avoid cutting the hair except at the weft seam. I sewed up the seams with a short stitch length to keep the cut weft from unravelling. I tried the wig on again for fit, trimming down the excess wig cap/ wefting as I went. This helped remove the bulk so I could judge the fit more accurately. I did this several times, slowly making the wig smaller, as I didn't want to over-cut and make the wig too small.
Wig reduction taken in fairly evenly on back seams

http://www.flickr.com/photos/delbelcoure/5352759836/

I made sure to avoid the rooted part line


http://www.flickr.com/photos/delbelcoure/5352150561/

When I had the fit I wanted, I top stitched the seam to one side to reduce bulk and to secure the cut ends of the weft a little more. During this whole process, I was as careful as I could be to keep the hair out of the seam, just like one does while sewing fur.

http://www.flickr.com/photos/delbelcoure/5352760428/

The alteration is unnoticeable from the right side

http://www.flickr.com/photos/delbelcoure/5352149801/

Here it is on Aubrey (it's a little small on him. I altered it to fit Ellowyne, but she's OT on DOA and I didn't bother hauling her out for a picture shoot)

http://www.flickr.com/photos/delbelcoure/5352149105/

Wow, that's really very clever! It looks perfect. Thank you for sharing.

I know its a year later, but thank you for this. I bought a wig a size too big for my sprite and want to make it fit. Now you have given me an idea.

I know I'm super late responding, but - you're welcome