Data::Dumper:
$VAR1 = {
          ' location_1' => {
                             ' tool_3' => ' 1
',
                             ' tool_1' => ' 1
'
                           },
          ' location_3' => {
                             ' tool_5' => ' 3
',
                             ' tool_3' => ' 2
',
                             ' tool_4' => ' 4
'
                           },
          ' location_4' => {
                             ' tool_5' => ' 3
',
                             ' tool_2' => ' 5
',
                             ' tool_4' => ' 2
'
                           },
          ' location_2' => {
                             ' tool_5' => ' 5
',
                             ' tool_1' => ' 4
'
                           }
        };
<ToolLocations>
   <ToolLocation>
       <LocationName>0</LocationName>
       <ToolList>
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       </ToolList>
   </ToolLocation>
   <ToolLocation>
       <LocationName>0</LocationName>
       <ToolList>
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       </ToolList>
   </ToolLocation>
   <ToolLocation>
       <LocationName>0</LocationName>
       <ToolList>
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       </ToolList>
   </ToolLocation>
   <ToolLocation>
       <LocationName>0</LocationName>
       <ToolList>
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       <Tool>
           <ToolName>0</ToolName>
           <ToolNum>1</ToolNum>
       </Tool
       </ToolList>
   </ToolLocation>
</ToolLocations>