Discharge them till the cells are around 3.3v. Disconnect all cabling so there is no
current drain and let them sleep. When you return, connect every thing up again and they will be ready to go. You will need to charge them to better than 3.45v rested in each cell group and discharge them down to 3v in each cell group, that is not all the cell groups added together and an average of 3v and 3.45v, you need to actually
monitor the cell voltages. Only requires one full cycle and they will be back to full capacity, or just let them cycle normally and after around 10 cycles they should be back to full capacity.
T1 Terry