Increasing the field length in master data items

Hi all,,

Can anyone say me how do i increase the field length of existing infoobject or infocube,, Say for example if i have product hierarchy which has 6 levels each level has a length of 3 and if i want to increase the length by 4 for all the levels of existing cube or infoobjects which has the data. wat should i do ,, wat are the steps that i ve to follow to achive this. Will it affect the upcoming data to the cube or infoobject,,

Ill assign points for it,,

Please reply

regards

dinesh