Best way is to do this with CSS.
Step 1
Download FontAwesome (260Kb).
Unzip all to C:\AwareIM\Tomcat\webapps\AwareIM\FontAwesome\
In Startup.html, add
<link rel="stylesheet" type="text/css" href="FontAwesome/css/font-awesome.css">
under the <!-- CSS Separator line -->
Step 2
In your BO, go yo Yes/No attribute > Presentation > Tick 'Save form when checkbox ticked or unticked'
On your custom form, this is your buton (Change the process names in the code below):
<<IF BO.myYN<>'Yes' THEN SHOW SECTION START>>
<a href="javascript: void(0);" onClick="AwareApp.startProcessFromForm ('myProcessToTickYes','main', this, false)"><i class="fa fa-square-o"> </i> Select</a>
<<SECTION_END>>
<<IF BO.myYN='Yes' THEN SHOW SECTION START>>
<a href="javascript: void(0);" onClick="AwareApp.startProcessFromForm ('myProcessToTickNo','main', this, false)"><i class="fa fa-check-square-o" style="color:#228B22; !Important"> </i> Selected</a>
<<SECTION_END>>
Place the processes in the form's Auto-Refresh.
Hope this works for you.
Cheers