You'll need The 'Thanks' ajax button installed and 2 icons you want to use.
 
Preview Images:
-My Thanks Button:
 -My Remove Thanks Button:
 
You can change the icons to whatever you want.
 
Here are the instructions:
Thanks Button
 
Go to : Admin CP Look & Feel Manage Skin sets & template « » Topic View ajaxThanksButton
 
Find this code:
<a href="javascript: ajaxThanks( '{$post['post']['pid']}' );" title='{$thislangwords['en30_thank_author']}' class='ipsButton_secondary'> {$thislangwords['en30_thank']}>
 
And replace with this:
 
<a href="javascript: ajaxThanks( '{$post['post']['pid']}' );" title='{$thislangwords['en30_thank_author']}' class='ipsButton_secondary'><img src="IMAGE LINK" >{$thislangwords['en30_thank']}</a>
 
 
3) Save and it should come out with something like this:
 

 
 
 
 
 
 
-Remove Thanks Button
 
 
Go to : Admin CP Look & Feel Manage Skin sets & template « » Topic View ajaxThanksButton
 
 
 
Find this code:
<a href="javascript: ajaxRemoveThanks( '{$post['post']['pid']}' );" title='{$thislangwords['en30_unthank_author']}' class='ipsButton_secondary'>{$thislangwords['en30_unthank']}</a>
 
 
And replace with this:
<a href="javascript: ajaxRemoveThanks( '{$post['post']['pid']}' );" title='{$thislangwords['en30_unthank_author']}' class='ipsButton_secondary'><img src="IMAGE LINK" >{$thislangwords['en30_unthank']}</a>
 
 
3) Save and it should come out with something like this:

 
The Originally posted by Sanctuary on forumcore with slight edits..