Follow the install guide here. Going through the standalone version, ensure that the Java JDK is installed. Obtain the latest Confluence archive, note: 2.5.6 has a bug that will not allow LDAP authentication to work properly. Also following trying to use the old database with LDAP authentication will open up this bug.
With Solaris, there is no need for the X11 libraries. The home directory is where Confluence data will be kept, Confluence itself is in the archive. Go to the Confluence Setup Wizard Guide. Create the admin user.
Follow this. Note Step 3.2. Step 5 must be successful. For Step 6, refer to this and this. There is a problem with linking LDAP users with their groups, currently both are shown but are not connected. Current solution is to create a Confluence group and use that.