It's not overly difficult, just time consuming.
What you have to do is use the parameters that are stated in the DS file as the information you need to imput in to TP to create the ADS or ADX.
Look for my 160 Baud ADX tutorial on the Tuner Pro site, IIRC it's in the Scanner Pro forum. There are some differences when building an 8192 baud ADS/ADX, but most of the information is a straight across copy.
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here are a couple links:
160 Baud ADX tutorial
A thread I started previous to the one above, that has some information about the bitmasks and such that can get a bit confusing:
Creating ADX files...
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