Motorized automate/manual push button system

A method of installing a driving mechanism into an existing flush apparatus which comprises a valve body having an operation opening, a water valve normally being retained at a sealed position, and a manual operation unit to move said water valve from said sealed position to an unsealed position, wherein the installing method comprises the steps of:

• (a) removing said operation unit from said valve body at said operation opening thereof;
• (b) coupling an actuation housing, having an actuation channel, with said valve body at said operation opening, wherein a motorized unit is supported in said actuation housing;
• and
• (c) aligning an automated plunger arm with said water valve at a position that said automated plunger is transversely supported along said actuation channel and is driven by said motorized unit, wherein when said motorized unit is activated in responsive to a presence of a user, said automated plunger arm is driven to move forward for moving said water valve from said sealed position to said unsealed position while said diaphragm member is then moved back to said sealed position.