Import the new list into the worksheet with the old file, then click Data, Remove Duplicates.  

Does anyone have any good tips on how to do this?

Also any South Florida  Investor with experience with LAFT property tip/advice about to get started?

Here are few tips on how to avoid this problem on your flips:1) Create a file folder for you flip (both electronically and in paper form), so you get and maintain the proper documents stated below.2)  Draft a summary general contractor (if you are the GC) plan or have your GC prepare a plan on what work will be done before you start it.3) Identify and create a list of all subcontractors that will be used.4)  Identify all materials that will be needed or used for your flip.5) Prepare all lien waivers for all subcontractor and materials either before the process starts (this is ambitious - but is a great idea)  or at the time of paying your subcontractors.  6) Lastly, get all lien waivers to your attorney prior to the actual closing.  

I do as a few above too; some 18 MHs on their own land, rent to own, seller finance after 12 months (long term cap gain), using an LMLO.Too much Dodd Frank tipping here for me

@Astrid Cuas Thank you for the tip, definitely will try.

All tips and advice is appreciated!

Any tips on getting started in the Staten Island market in 2016?

Any left-field tips for a beginner you're dying to share?

I am looking for any tips or advice anyone can give.