How to customize the "Read more" link in D7? By default, the "Read More" link wrapped in the tag &lt;li&gt;. How i can change this tag to &lt;p&gt;? 

I tried to use hook theme_node_view_alter(&amp;$build), but i couldn't find in $build required variables.
node_build_content is where it's originally set. You should be able to override this by implementing hook_node_view or hook_entity_view. The links should be in $node-&gt;content['links']