300 gear box and transfer change

can anyone help me please? my gear box has given up the will to work anymore so i'm having to cahnge it, it is the first time i have had to change this and i'm looking for advice on weather its a big job that i can do on my own( with help of friends) or is it a garage job? i have little experiance with mechanial work and most tools, will i need a specail tool, ? can anyone help?

If you own a trolley jack it's a simple job but will need a friend to help out as it's a heavy bugger to do on ya own. No special tools required