Reg Z Modification Agreement on HELOC

We currently have Home Equity Lines of Credit (open ended) that have floor rates of 6.00% and 7.00% and we would like to reduce these to our new floor rate of 4.25%. I know under Reg Z Section 226.5b (f) it states we can make a change that will unequivocally benefit the consumer throughout the remainder of the plan. With that being said what type of documentation and disclosures must be given in order to stay in compliance with the regulators and terms of the loan? We want to ensure that if we do a modification agreement on the HELOC we do not need to redisclose on the loan.