Upgrading nutch 1.8 for having solrj 4.9

[Ali Nazemian]

Dear all,
Hi,
I need to make some changes in solr-index plugin. For this purpose I have
to upgrade solrj to 4.9. The problem is for changing solrj I need to change
other parts of nutch source code. It seems that some of applied libraries
are out of date for solrj. Is there any body that already did this process?
Could you please guide me what libraries need to change for this purpose?
Regards.
-- 
A.Nazemian