Shareholder agreement reviewed and amended with full advice.

I am selling some of my shares to my business partner. We have already discussed and negotiated terms and my business partner has had the agreement written by his solicitor.
I would like someone to read through the agreement to make sure I haven't missed anything, and to receive any advice that may lead to you amending/rewording the current agreement.
We have already contacted HMRC to have their approval for the company to buy the shares from me.
I would like a fixed fee for this work and the aim of this project it that I will be 100% confident that I can sign the agreement.
Many thanks