There are many ways to edit them, but I don’t know if there are BEST ways to do it.

One way is using a photo editing application like PaintShop Pro or Adobe Photoshop.

One way is following the Microsoft instructions ( http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdi/metafile_0hmb.asp):

Editing an Enhanced Metafile
To edit a picture stored in an enhanced metafile, an application must perform the tasks described in the following procedure.

To edit a picture stored in an enhanced metafile

• Use hit-testing to capture the cursor coordinates and retrieve the position of the object (line, arc, rectangle, ellipse, polygon, or irregular shape) that the user wants to alter.

• Convert these coordinates to logical (or world) units.

• Call the EnumEnhMetaFile function and examine each metafile record.

• Determine whether a given record corresponds to a GDI drawing function.

• If it does, determine whether the coordinates stored in the record correspond to the line, arc, ellipse, or other graphics element that intersects the coordinates specified by the user.

• Upon finding the record that corresponds to the output that the user wants to alter, erase the object on the screen that corresponds to the original record.

• Delete the corresponding record from the metafile, saving a pointer to its location.

• Permit the user to redraw or replace the object.

• Convert the GDI functions used to draw the new object into one or more enhanced-metafile records.

• Store these records in the enhanced metafile.