Costomize EMail Notification

Hello,

I´d like to customize the notification email.

Since I can´t find a documentation of the used methodes (/xwiki/bin/view/XWiki/Notifications/MailTemplate → Objects ), I can´t costomize it.

$services.localization.render('notifications.email.title')

#foreach ($event in $plainTextEvents))
-------------------------------------------------------------------------------
$event.trim()
#end
#template('notification/email/macros.vm')
## Main Div
<div style="font-family:'Open Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 12px; background-color:#F5F5F5; padding:15px; margin:0 auto; color: #1d1f24; ">
  ## Main centered table
  <table style="max-width: 570px; margin:0 auto" cellspacing="0" cellpadding="0" width="100%" align="center"><tr><td>
    ## Logo table
    <table width="100%" border="0"><tr height="55px">
      ## Logo
      <td align="left"><a href="$xwiki.getURL($services.wiki.currentWikiDescriptor.mainPageReference)"><img src="cid:logo" alt="XWiki" height="50" style="height: 50px"></a></td>
      ## Notification settings
      <td align="right"><a href="$xwiki.getURL($emailUser, 'view', 'category=notifications')" style="color: #0088CC; text-decoration: none; font-size: 14px;"><img src="cid:NECog.png" alt="" height="12" style="height: 12px"/> $escapetool.xml($services.localization.render('notifications.settings.title'))</a></td>
    ## End of the logo table
    </tr></table>

    ## Events div
    <div style="background:white;padding:1em; border-left: 1px solid #eaeaea;border-right: 1px solid #eaeaea;border-bottom: 1px solid #ddd;border-top: 1px solid #f0f0f0;">
      <h1 style="font-size:30px;font-style:normal;font-weight:500;line-height:42px;letter-spacing:normal; margin-top: 0;font-size:21px;">$escapetool.xml($services.localization.render('notifications.email.title'))</h1>
      ## Display a table of content
      #displayTOC($sortedEvents)
      ## Display Events
      #foreach ($list in $sortedEvents.values())
        #foreach ($sortedEvent in $list)
          #displaySortedEvent($sortedEvent)
        #end
      #end
    ## End of the events div
    </div>
  ## End of the main table
  </td></tr></table>
## End of the main div
</div>

Do I have to edit the ‘notification/email/macros.vm’ in the filesystem?
Or is there a better / safer / easier way?
Best case would be a documentation where the used methodes are explained.

Thank you guys.