This is covered in the OP15 / OP5 manual under "commissioning". You should be able to download this manual from the Siemens web site.
There are several ways of putting the OP into download mode, with the correct way depending upon where you are starting from. Normally you select download mode from the system menu. If this does not work, then I suggest you read the manual for more details.
Dear you have to reset the op5 to download and note that
1. you cannot append the screen directly but u should have orignal program to modify and then downloads it after reseting.
2. also you cannot upload the program from op for modification.
To reset just press the right, down and i think ins key at a time and then switch it off and bring it up again after that it will show READY TO DOWNLOAD... You can find this method in manual of OP5.
