Can I revise W/L ratio at the LTspice?
You're using the wrong symbol. You need to use nmos4 for integrated circuit MOSFETs, as shown below.  Don't forget to connect the body terminal to the correct spot for each FET in your application.



Then if you rightclick on the symbol you can set the model name and the instance parameters.



Afterward, you can shift+rightclick the symbol and then double-click the Vis. square for the instance parameters so they show on the schematic.  If you do this, it also makes it easier to edit L and W later since you can just rightclick on the text directly.



Lastly, you should define a .model statement with non-default parameters.  See the LTspice help (press F1 key) for more information about M. MOSFET.  The last image below is a rough representation of what a final schematic could look like.