How to replace the string values stored with in a variable in objective c

I got an xml in output for the webservices.I have the result in the variable and i stored the result in that variable.Now i want to replace the strings in that variable.How to replace the strings in that variable. For ex:

//SDZZmaterialGroupList* result = (SDZZmaterialGroupList*)value;

in that result variable i stored the result is:

</Text></item>

<item>

    <Matkl>00101</Matkl>

    <Text>Steels</Text>

</item>

<item>

    <Matkl>00107</Matkl>

    <Text>Miscelleanous</Text>

</item>

<item>

    <Matkl>002</Matkl>

    <Text>Electronics</Text>

</item>

<item>

    <Matkl>00207</Matkl>

    <Text>Monitors</Text>

</item>

<item>

    <Matkl>003</Matkl>

    <Text>Bulbs</Text>

</item>

<item>

    <Matkl>007</Matkl>

    <Text>Services</Text>

</item>

<item>

    <Matkl>008</Matkl>

    <Text>Packaging</Text>

</item>

<item>

    <Matkl>01</Matkl>

    <Text>Material Group 01</Text>

</item>

<item>

    <Matkl>02004</Matkl>

    <Text>Parts</Text>

</item>

Now i want to replace the tags with empty value so that i can display the values(numbers) only in the iphone? Let me help out of this problem?