I would immediately notify the seller in writing that the home inspection had issues that you did not find acceptable. Define exactly what the issues were and if possible support with copies of the pages of inspection that address the issues. I would not send the whole copy of the inspection. Then I would state what you propose as a resolution, whether the seller fixes it or a price reduction.
This is all assuming you signed a Contract to Purchase with a home inspection contingency.
In the common case, one often makes an offer where one of the contingencies is a Home Inspection contingency ... either to the satisfaction of the buyer or to some dollar amount. This is the contingency that would allow the buyer to potentially renegotiate the price without risk of his/her earnest money in the case that some unexpected issues came up in the Home Inspection. There really isn't any form per se so much as the terms of the Purchase and Sale Agreement. Am I correct in assuming that this has not been agreed upon and signed yet?
I realize you may not want to share all the details of your transaction on a public discussion group. However, how you proceed does depend on the details of your particular situation. Feel free to contact me offline at firstname.lastname@example.org or (781) 304-1048 if you do not already have a real estate attorney or representative to help you.
Hope that helps!!
You may have to furnish a copy of the home inspection report detailing the issues found that your not happy with and ask for the concessions in writing. The seller/owner has 3 options, accept your proposal, reject your proposal or counter offer your proposal. Were the items you are unhappy with items that needed professional observation to recognize or was it something that should have been obvious to the general home purchaser? An example of this would be a structural issue in a wall that only a professional inspector/contractor would recognize or simply an old roof/kitchen needing updating/replacing. You'll also have to look at what was disclosed on the listing sheet, sellers disclosure etc.
If you did alot of negotiations to get the offer accepted they may be less receptive, but that's an unknown. I don't know your sellers, their motivation or anythng about the property. Hopefully you at least have an attorney representing you, that way someone is looking over the contracted agreement and can suggest options.
Your inspection contigency in the original contract states how quickly you must inform the seller of your dissatisfaction with the inspection, whether you musrt provide the seller with a written report from the inspection, and whether the seller has the option of resolving those issues by making repairs/replacements, etc. rather than granting an allowance to you. Check with your agent, if you have one. Otherwise, reread that section of your purchase agreement, present the seller with your preference for a price reduction, and cancel the contract before any time limits have expired if you're not satisfied with the answer. You can always write a new contract if the situation changes.
Hope that helps.