Its is possible to replace the glass only. You must heat the glass to 280 degrees and use a wedge on both sides to SLOWLY lift the glass. You will see the glass desperate from the glue. Keep the glass hot enough before lifting upwards. I have successfully does this procedure over 10 times even with shattered glasses. Its time consuming but be patient.
Also the bottom is NOT fused, the soft keys are adhered to the glass so you must use a plastic wedge to peel them off. Also you must remove all the old glue from the LCD and you do not need to replace that. Just use some doublesided tape on the edges.