Kernel build and git

[Pratyush Kshirsagar]

Hello,After building a customized kernel in /usr/src.I made a branch of the master git node. Further, made some changes in the /usr/src/usr.bin/top/machine.c,The # git diff command showed me the appropriate changes. 
When I am installing the kernel again, it does not show me the desired output for # top command.But, when I do make in the /usr/src/usr.bin/top/ directory and use the object file "top" it shows me the output with changes.
What should I do to incorporate all the changes made in /usr/src tree in my running system, the way we do in linux.If I am able to do all this things, I can go with adding some code in the /usr/src/sys/kern directory and test it on my customized kernel.
Have a nice day :)Pratyush Kshirsagar.