Yes, you can do this in TypeTool. There are two different options that spring to mind.
To just adjust the spacing and leave the glyphs alone.... In the font window, go to the menu:
Tools > Actions > Metrics > Set sidebearings.
Change the popdowns to make the Left SB "Decrease by" and the Right SB "Decrease by" and then set both to decrease by 69 units. Check the box that says "apply to entire font." That will reduce the total advance width by 138, or from 640 to 512.
However, then probably the spacing will seem much too tight. You could also do this by scaling the glyphs. The spacing will then be good, but the glyphs will be somewhat distorted. Your call. To scale the glyphs, you would want to scale them horizontally only by 512/640 or 80%.
In the font window, go to the menu:
Tools > Actions > Contour > Scale
Select Horizontal scale of 80 and leave vertical at 100. Check both "Scale hints" and "Scale metrics" and leave it centered on the Origin point. Check the box to "Apply to entire font" and away you go.