Bioequivalence and Bioavailability Forum

Dear all,
Please let me introduce myself first: I am a beginner in BA/BE study field, working for just-established BE center. Therefore, my question might annoy you, please forgive me and understand for me that I have tried my best to improve my basic knowledge on BA/BE and I have searched thoroughly all topic in this forum.
The problem of our center is: all of us are pharmacists, we do not have deep knowledge in statistic. Also, we do not have any statistical software (I found the free software "bear" introduced in this forum and am trying to apply it at the moment - thank you for introducing!). With a very basic requirement of FDA for bioequivalence, we still do not understand what have to do, please help us:
1. In Guidance for Industry: Statistical Approaches to Establishing Bioequivalence - FDA, 2001, page 10: The 90% CI for the difference in the means of the log-transformed data should be calculated using methods appropriate to the experimental design. The antilog of the confidence limits obtained constitute the 90% CI for the ratio of the geometric means between the T and R products.
So, the first CI for the difference in the means... calculate with which mean:arithmetic?
We only think that calculate CI of the geometric mean ratio means using geometric mean, can't understand why have to do antilog.
2. In the report format of ASEAN, it is required to have a table: - Table - Analysis of Variance, Geometric least-squares means for each pharmacokinetic parameters.
We do not know how to calculate geometric least-square means? Could you please tell us step by step the equation to calculate? Because, even if we are able to use the software Bear, we still have to validate it, i.e calculate manually to compare the results. Also, I myself, really want to understand clearly what LS-means is so I am confident to talk about it. I have read http://www.uidaho.edu/ag/statprog/sas/workshops/glm/lsmeans.htm
but still not understand very well, especially when we have a big data.
I am really sorry for such long question. Hopefully you are not too tired to read my poor English. Really waiting for your help. Thank you in advance!