B76,b77 and b78 have to be squished.Here's a few pictures to show this process.First what they look like without the squish. (For a moment just forget about the rtl). Then in the attachment thru the wonder of paint i show the three bars squished into two.The attachment shows just b78 squished with b76 because of decreasing volume internal on b77. Turns out after the squish i have a XR.So do i fan the rtl from b77 to b78? I don't believe so.I should not have fanned mine.Only after doing the squishes can you fan if the resulting price case is an internal.As you can see this can be a challenge (at least for me on this one) since you have to do this mentally and not with paint. http://screencast.com/t/a9h7Gbjoj