Sometimes I wanted to do smart partitions, by doing separate /boot partition, but I only give little space. Now I am having problems with lack of space on that partition.
How to remove /boot partition and join it with /root partition?
You could use
Once you verify that everything is fine you can remove
You could also just keep the /boot partitition and expand it with gparted. (Of course, as always, backup first and keep a liveCD handy in case something goes wrong)
If you've never resized partitions before, there are plenty of tutorials on the web that will tell you how to do it. Here's a good tutorial to start with: http://www.ibm.com/developerworks/linux/library/l-resizing-partitions-1/index.html