This page explains the kernel recompilation process.
The first thing you'll need to do to recompile the MeeGo kernel is to download and unpack the MeeGo kernel package. To get that package you can download it with wget like this;
wget http://repo.meego.com/MeeGo/releases/1.1/core/repos/source/kernel-2.6.35.3-10.3.src.rpm
You can of course get your kernel directly from upstream at kernel.org for example.
If you take the packaged MeeGo kernel, then you'll need to unpack this rpm. You can do that this way;
rpm2cpio kernel-2.6.35.3-10.3.src.rpm | cpio -id
and spot the linux-2.6.35.tar.bz2 file and patch-2.6.35.3.bz2 git clone git://gitorious.org/meego-os-base/kernel-source.git