Yes op, you can change you password as it is always advisable to use a strong password. If you feel a need or become security nervous you just have to reach for your profile and account related setting.
After you are done imputing the new password you have to write in the old password and click on the change profile button below.
Here's a link on how to go about some profile security settings and how to recover your account.
Forum account: security, privacy, and recovery