I use a Oppo Find 5 smartphone but the default icon pack is quite bad looking, I was wondering if there was a way of changing ONLY the menu icon and the size of the rest on the dock.
Install either Holo Launcher HD or Holo Launcher, whichever is compatible with your phone and make it the default launcher. :) Links to the two apps are [BROKEN LINK REMOVED] or https://play.google.com/store/apps/details?id=com.mobint.hololauncher
Which ROM version are you using? (Go to Settings, About Phone, and it should list the android version and a name for the version of Android, like PAC rom or CyanogenMod) You might be using ADW Launcher or other third party launcher, which you should be able to press the Settings button (the soft key that has the three lines on it) and should bring up a menu for changing settings. Within the settings should be the ability to change the icon size, font size, theme (where you can download and use different icons and colors for the system and applications, including the App Drawer icon), and other settings. Each launcher is different, so we would need to know the launcher name to give better instructions on how to do what you wish.