i'm running slackware9...

this is real easy...
download kernel source 2.5.69 from www.kernel.org,
or some other website.

the only prerequisite for kernel 2.5.69 is to update binutils.
updating binutils is easy, its just a matter or 3 commands.
first you have to download it.
kernel 2.5.69 shows you where to find binutils (inside Docs/Changelog)

to install binutils....
./configure
make
make install

place the kernel 2.5.69 in /usr/src/
bunzip2 it or gunzip it, or tar it

rename the directory to linux...
mv linux-2.5.69 linux

cd /usr/src/linux to change into the kernel source directory.

then....
kernel 2.5.69 kicks ass...

make sure you provide support for WAN's when using make menuconfig.

to compile the kernel...
you only need to run 3 commands to compile the kernel.
make dep is no longer an option with 2.5

make mrproper
make menuconfig
make bzImage

after copying bzImage to the /boot partition and reconfiguring lilo...

a quick reboot and your wireless router should work.