Complex casting

After learn C and theorical stuffs of operatives systems, i decided to analyze one kernel rootkit for linux, but i can't understand one line of code, i don't know how to read that line:

*(void **)&((char *)h->original_function)[ASM_HOOK_CODE_OFFSET] = h->modified_function;

Full context:

#if defined __i386__
    // push 0x00000000, ret
    #define ASM_HOOK_CODE "\x68\x00\x00\x00\x00\xc3"
    #define ASM_HOOK_CODE_OFFSET 1
    // alternativly we could do `mov eax 0x00000000, jmp eax`, but it's a byte longer
    //#define ASM_HOOK_CODE "\xb8\x00\x00\x00\x00\xff\xe0"
#elif defined __x86_64__
    // there is no push that pushes a 64-bit immidiate in x86_64,
    // so we do things a bit differently:
    // mov rax 0x0000000000000000, jmp rax
    #define ASM_HOOK_CODE "\x48\xb8\x00\x00\x00\x00\x00\x00\x00\x00\xff\xe0"
    #define ASM_HOOK_CODE_OFFSET 2
#else
    #error ARCH_ERROR_MESSAGE
#endif

struct asm_hook {
    void *original_function;
    void *modified_function;
    char original_asm[sizeof(ASM_HOOK_CODE)-1];
    struct list_head list;
};


/**
 * Patches machine code of the original function to call another function.
 * This function should not be called directly.
 */
void _asm_hook_patch(struct asm_hook *h)
{
    DISABLE_W_PROTECTED_MEMORY
    memcpy(h->original_function, ASM_HOOK_CODE, sizeof(ASM_HOOK_CODE)-1);
    *(void **)&((char *)h->original_function)[ASM_HOOK_CODE_OFFSET] = h->modified_function;
    ENABLE_W_PROTECTED_MEMORY
}

Rootkit link: https://github.com/nurupo/rootkit/blob/master/rootkit.c (line 314 of rootkit.c)

I don't want to be explained how the rootkit, only want to understand how to read that line of code, the first part of the line makes me dizzy.

If I am not mistaken: you start at the innermost part, which is

h->original_function

Then we see a brace at the right so now we scan left for the matching brace. But wait a second, we see a cast to (char *) so it is a pointer to a char and now the brace closes.

On the right we now see an array indexing to take element [ASM_HOOK_CODE_OFFSET] and on the left we now see & to take its address. So we now have the address of a char.

Now we can only go the the left and see *(void **), which casts this address to be a pointer-to-a-pointer-to-void and then dereference it and assign the right part to the address.