If you've forgotten your CRM password, you can follow these instructions for resetting.
If you know your password but want to reset it, from within your CRM go to Manage Your Account:
Then, click Manage Database Users & Teams in the Admin section:
From this page, locate your name in the Current Database Users section, click your Actions menu and then select Change Password:
You would then see the below:
Then, it's just a matter of typing in your current password (in the first field), new password, confirming the new password and clicking Save. Note that the username for whom you are changing the password is displayed above the the two boxes for the new password and confirmation.
Note: You must be an admin user of the database in order to have access to the Manage Database Users & Teams page. If you are not, you would need to reset using the reset method described here.