Answer: Insert one or more special clauses in an addendum to the contract.
Step-by-step explanation:
The standard provision are assumed to apply to every contract especially when signed on a pre-printed contract agreement that contains such standards.
In the above scenario the provision of the sales contract in a pre-printed sales contract applied to the parties.
To give validity to the contrary terms an addendum of it has to be added to the standard of the pre-printed sales contract.
Re- negotiating or listen the contrary terms does not give validity to it, neither does preparing a non standard contract.