"(how to) reset admin password on server configured with LDAP
(i'm) not able to change admin password from splunk web. splunk server is configured with LDAP authentication and cannot change admin passwd from splunk web."
I see there are a bunch of questions asked related to this but perhaps one more answer cannot hurt.
In Splunk ver. 4.0.x and previous, EITHER LDAP authentication or Splunkauth can be setup (and NOT both).
In newer versions of Splunk (as of 4.1.x) side-by-side LDAP and Splunkauth is supported. This means that authentication can be done for users using both LDAP and Splunkauth, as long as the two do not conflict.
In the person's above case, they were on 4.0.x, hence in order to change the admin password they need to go back to the LDAP UI to configure it. This cannot be done through Splunk Web because Splunk ONLY reads from LDAP and does not (cannot) write to it.