To change the time on the LG microwave MH6535GIS, follow these steps:

1. make sure the microwave is switched off.
2. press the 'Clock' or 'Time' button (depending on the model, the name may vary, but it is usually a button with a clock symbol).
3. use the number buttons to enter the new time. Set the hours and minutes.
4. confirm the entry by pressing the 'Clock' or 'Time' button again.

These steps should work in most cases, but for specific instructions I recommend consulting the microwave's user manual if you have it.