To take partial profit on MT4, you need to modify your current order and do the following steps:

Go to the MT4 Terminal and choose the “Trade” tab.

Choose your live order, click the right mouse button, and select “Modify or Delete Order.”

Choose from the Type list “Market execution.”

Change the volume value that you want to lock in profit. In this section from the volume of 0.04, we will partially close the 0.01 lot

Select the close trade option.

*Please note that it will work only for the minimum volume of 0.02 lot