Open System Preferences (2nd item down in the menu)
Select the Sharing prefpane
Click on the lock icon in the lower left, then supply admin credentials
Check checkboxes "Screen Sharing" and "Remote Login"
click on the text "Screen Sharing", then select the radio button for "Only these users...", then the "+" below the user list you will get a list of accounts enabled on this Mac - select the appropriate user(s), then click/tapthe blue "Select" button
go through the same process for "Remote Login"
Make sure the "Remote Management" checkbox is unchecked
Click on the lock icon in the lower left again to lock the prefpane