It's little late to reply your message, but I hope this message can help to other people with the same doubt.
In order to do a tidal analyisis, basically you require a time serie or record with two variables: dates and sea levels.
Once you have your sea level record, you will need a software to compute the tidal analysis. Due to we are in Matlab Answers, I recommend you Pawlowicz's T_Tide Matlab toolbox (version 1.4). This toolbox is an excellent tool.
You should read the Pawlowicz's paper: Pawlowicz, R., Beardsley, B. and Lentz, S. 2002. Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE. Computers and Geosciences, 28, 929-937.
For more details about how to run T_Tide, you should review t_demo.m script of the toolbox.