No, it will never be possible. The ranks are established to elimate possible trolling, site vandalism and uniformed updates done by virtually nobodies.
The rank system ensures, that the substantial updates will be done by veteran, users who are experienced and by whom you can expect at least to a certain extent a quality work.
http://www.metal-archives.com/help.php
http://www.metal-archives.com/faq.php
Can you make the following changes to band X's page?
E-mails are not the correct way to ask for changes that you can't make by yourself. There's a "Report a mistake or additional information for this page" link on each band page that can be used to report information that needs changing. You can also provide links to new pictures, see the question about images further down for more info.
http://www.metal-archives.com/guidelines.php
The rules are very simple and explained in detail. If you do not understand them, then the problem is on your side.
http://www.metal-archives.com/help.php#update
Is the section above impossible to find or what???
Updating an existing band
If your member rank is Veteran or higher, you can modify all the fields except the band's name and its genre. You can change the pictures as well, but you cannot delete them.
Please don't be an asshole; don't delete or tear apart huge chunks of texts (for example, the bios Ultra Boris wrote for Overkill, Metallica, etc.) for whatever reason. Ignore this warning and you might very well get banned! Be reasonable in your editing - you CAN edit out useless information IF (and only IF) you are sure that the text breaks the rules (self-promotion, just enumerates the discography, is just pasted from the official website...). Thanks.
If your rank is lower than Veteran, you can only write in the optional missing fields. For example, if the band does not have a logo, you can upload it; if the lineup is missing, you can add it; but you cannot change the actual logo or edit the lineup if they have already been entered.
Updating existing releases for a band
If your member rank is Veteran or higher, you can modify all the fields except the release's title. You can change the cover art but not delete it.
If your rank is lower than Veteran, the same restrictions for updating the bands apply: you can fill in missing data, but not change the current data.
Updating links for a band
If your member rank is Veteran or higher, you can modify or even delete any link. This is of course in case the link doesn't point to a page that's still active anymore; if the page's new URL cannot be found, you can simply delete it.
Members with a rank lower than Veteran cannot modify any link and can only add them.
Updating your review
Regardless of rank, members can edit their own reviews whenever they want. However, since the reviews are moderated, updates to existing reviews must be approved before they appear. So if you change anything in your own review, it will become temporarily invisible to the visitors until a moderator re-approves it, regardless of the nature of the change! So it would be best if you proof-read your review *before* it is approved or else it will have to be re-approved again. It may be irritating if you just want to change your rating, but it's a precaution we have to take.
Members can also delete their own review as they see fit, but it shouldn't be necessary since you can always just modify it. To update your review, go to the band's page and scroll down to the album, and click "add review", as if you wanted to write a new one. It'll take you to your own review, which you can edit.