how to unpatch?

[eric lin <fsshl@centurytel.net>]

Dear Linuxer:

  I follow the Readme in 2.5.50, do
 gzip  -cd patch-2.5.50-ac1.gz | patch -p0

but then it response

can't find file to patch at input line 4
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:
--------------------------
|diff -u --new-file --recursive --exclude-from /usr/src/exclude 
linux.50/arch/alpha/defconfig linux.50-ac1/arch/alpha/defconfig
|--- linux.50/arch/alpha/defconfig      2002-11-25 15:11:47.000000000 +0000
|+++ linux.50-ac1/arch/alpha/defconfig  2002-12-03 20:54:30.000000000 +0000
--------------------------
File to patch:

then how should I response?
I ever try to put again
atch-2.5.50-ac1.gz

but it is not work,

please give more hint to unpatch
highly appreciate your time and effort
sincere Eric
www.linuxspice.com
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