Close -- you missed this part "It will also add a space after the path. Delete the space at the end of the path."

Just copy and paste the following line into the terminal window and hit return:
/Users/melyasuryanto/Desktop/aMule-Mac.CVS.2006-06-03.noDebug_Panther\ Folder/aMule.app/Contents/MacOS/amule
EDIT:Wait, it looks like you actually downloaded the completely wrong version:
"aMule-Mac.CVS.2006-06-03.noDebug_Panther.zip" is for Panther, the older version of Mac OS X, and does not run on the new Intel based Macs. Plus, it's a CVS version (i.e. a developer snapshot; for more information read the thread that is linked in my signature below), that needs to be started through the terminal with a particular switch.
The version you want to download is
this version.