Dumb question

OK I am a noob and I am going to change my timing belt and tensioner and the book says to put everything in a certin positon. Cant I just leave everything where it is and pull one off and slide the new one on?
EG6b20R wrote:it will be off timing and possibly not start up.
JohnAWESOME wrote:Hey thanks guys I changed it out old one was way past due. A little streched out and looked worn. The crank pulley bolt is problly what took the longest to get.