can i change a unit of measure(in the configaration settings

can i change a unit of measure(in the configaration settings)/ need to delete a unit of measure permanently of a material for which i have already done all the transactions for materials (accounts also being updated) if so where can i change the unit of measure?

Normally when you have created a material with a unit of measure and process transactions, so many tables in the system get populated with the units of measure for all the transactions you have done and it is very difficult to track all tables populated with data. . So if in the mid-stream you decide to change the unit of measure SAP recommends the change but subject to certain conditions:Changing the Base Unit of Measure PrerequisitesIt is only possible to change the base unit of measure in the following cases:If there are no stocks of the material in the systemIf there are no purchase requisitions, purchase orders, or scheduling agreements for the material.If a purchase order or purchase order item is not being created or changedIf requests for quotations, purchasing info records, or contracts exist for a material, the system merely issues a warning when you change the base unit of measure. If one of these later becomes a purchase order, you simply have to specify the factor for converting the order unit to the new base unit of measure in a dialog box. The purchasing info record is then updated if necessary.ProcedureAccess the material master record in Change mode. Overwrite the old base unit of measure with the new one on any departmental data screen. Save the change.ResultThe system checks whether the base unit of measure can be changed. If it cannot be changed, a message appears to this effect. Choose Display errors to display the reason.However all the old transactions you have done will have their history in the old units of measurement and the fresh transactions can only be recorded in the new unit of measure.An alternate solution will be:1. Copy the material to a new material with new unit of measurement.2. Upload the closing stock of the old material as opening stock of the new material through mvt. type 561.3. Update the moving average price/standard price of the new material in the accounting view.4. Conduct a physical stock verification of the material with old UOM and reduce the stock(s) to zero.5. Block the old material at the material master level for external procurement.6. Make necessary changes in the relevent BOMs.7. Issue a declaration to the concerned departments that with effect from a specific date they should transact with the new material and UOM instead of the old.I hope I have not missdd out on any major things.Please consult specialists from other modules in your company that there are no anomalies.