How to remove a line from a manifest file inside a jar, from the command line?

i need to remove a line from the MANIFEST.MF inside a jar, I tried extracting it and ge开发者_如何转开发nerating a new manifest and using jar umf to put it inside again, but it not worked and the line is still inside the jar. I do not want to rebuild the jar and neither do it manually using 7-zip, there are many files that I need to remove the exact key inside the manifest.

I need to remove this line because without this line the device I´m trying to install the midlets aborts the install with it.

Thanks.

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I solve this using the zip to replace the file instead of using the jar tool.