Step1
Ok This is really simple.
WARNING This only applies to remote controls with NO LCD DISPLAY & NO KNOBS TO TURN.
Remove batteries don't worry if they have leaked we will deal with this later.
Slide your blunt round ended knife between the two halves of the casing. Do this midway between top & bottom of the remote.
** NOTE only slide knife in 1/8 of inch or 3mm **
Now prise the casing apart use your screwdriver if it is difficult once it starts to come away work your way around casing until the two halfes are apart.
Step2
Now make a note of how the battery terminals are mounted to the plastic casing (draw a picture if you need to)
Now you need to remove the PCB (Printed Circuit Board) Depending on your remote this may have small screws holding it in place if it does remove them.
Lift PCB away from button bank. If the buttons are made of hard plastic just remove rubber membrane DO NOT remove buttons as well.
If your buttons are rubber they are moulded to the membrane & will come away in one piece.
Step3
NOW FOR THE GOOD BIT.
Run some hot soapy water & Immerse the PCB the rubber membrane & bottom side of remote casing in the hot water. If your rubber membrane has the push buttons moulded to it then Immerse the top of remote as well.
DO NOT immerse hard plastic buttons & upper casing if you have this type or you will spend the rest of the day trying to work out which hole they came out of.
Step4
Now squirt some detergent on to your dry paint brush & thoroughly scrub both sides of PCB take your time doing this.
Now scrub both sides of rubber button membrane, Clean remote casing paying attention to any battery terminals connected to the bottom casing.
Step5
Now rinse the casings in hot water & dry them with hair drier.
Drain the sink & rinse the soap from the PCB & button membrane.
Now fill your kettle & boil some water leave button membrane & PCB in the sink when kettle has boiled pour the boiling water over the PCB & button membrane leave sink plug out so water drains away.
Remotes are very greasy & sticky inside the boiling water ensures all foreign matter is washed off.
wait a few mins for the items to cool before picking them up.
Now thoroughly dry pcb & membrane with hair drier If your pcb has any integrated chips (ICs) shake PCB to ensure no water is trapped under them, Once dry inspect soldered joints any that look like they are cracked or the legs of components can move about in must be resoldered.
Step6
Now reassemble the remote which you do in reverse order of taking apart
Fit new battery's & test your repaired remote.
I know electricity & water don't mix but providing you completely dry everything after cleaning you will not have any problems.
Step7
Congratulate your self on a job well done.