Please note that once users use su to transform into root they will lose read/write access to their home directories. This is to protect students from accessing each other's private work. The problem with this policy is that you will not be able to install the kernel modules if you build the kernel source inside of your home directory. One way to approach this problem is to build the kernel source in a special directory (/kernels) which all users can see. You can move the kernel source into this directory and then su to root and build and compile the source code. You must realize that this is a truly public directory. You must remember to move files from this public location back to your home directory in order to maintain a copy of your work. You must not leave files here that other students can use for their solutions.
If you rebuild the kernel with a configuration that builds the Reiser file system (reiserfs) as a module rather than as part of ther kernel, you are likely to have build/install problems. You can ensure that reiserfs is built as part of the kernel by using make menuconfig as described below. There is a step by step description of steps you should follow to recompile the kernel below.