Implementing HJM for multi curve IR

[loic mongellaz]

Hi,

I currently have to accomplish a project. I need to implement HJM for computing multi-curve interest rates in the post-crisis context. I have read several papers on the subject but I think I do not understand what I really need to do.

First, I think that I need to calculate the forward on the LIBOR with a 1M tenor for instance, then the forward with a 2M tenor and so on, and then I will plot the forward rate for each tenor based on the maturity of the forward. Is it something that seems totally crazy or plausible ??
I need to consider the spread between different tenors.

Also, I have understood that HJM needs to be computed with Monte-Carlo but I cannot figure out which Stochastic Equation I should simulate.
For instance, I have an equation :

dF(t, T-x, T) = ...with modeled volatility
I also have F(t, T-x, T) = Et[ L( T-x, T) ]
Because I have'nt fully understand the concepts I cannot get how to use this formula to price the curves I was talking about earlier. My problem is not about math but more on what represents each product...

Thanks a lot to those who'll try to help me !

Loic