To get this task done, you must understand the circuit and how it works. For this, you need a thorough comprehension of analog circuit design, which will allow you to find estimated W/L values for your design. Then you will have to simulate the design and change device values (and possibly the design itself) often within several try-and-error loops until you get the expected and correct output. Besides a thorough knowledge of analog circuit design you need at least a basic understanding of the simulation tool which allows you to analyze your circuit (and which often can present results not easily to be understood, so you need to know the tricks how to get it working). Moreover, in order to get fast over such a design task, it needs a person with good experience with similar designs.
All this needs an education procedure which is provided by high schools and/or text book studies, which take quite a while, and which surely cannot be covered within the framework of a forum. Analog designers who can manage such a design still need some time to get it working - and get paid for such tasks.
What you want will take hours if not days to get it working, also depending under which environmental conditions (re. PVT ranges) the design should work - in an individual technology process with full PDK support and available design and analysis tools set up - even for an experienced designer.
Now decide if you will learn and manage it yourself, or get an analog designer to have it done - not me, BTW!
Good luck, anyway!