VB.net / C# Hack [Tutorial request]

using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace Namespace
{
    public class MemoryManager
    {
        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern IntPtr OpenProcess(UInt32 dwDesiredAccess, Int32 bInheritHandle, Int32 dwProcessId);

        [DllImport("kernel32.dll")]
        public static extern Int32 CloseHandle(IntPtr hObject);

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern Int32 ReadProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, [Out] byte[] buffer, uint size, IntPtr lpNumberOfBytesRead);

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool WriteProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, byte[] lpBuffer, uint nSize, IntPtr lpNumberOfBytesWritten);

        Process process;
        IntPtr baseAddress;
        int AddressLength;
        int ProcessID;
        IntPtr LinkHandle;

        public MemoryManager(string ProcessName)
        {
            process = Process.GetProcessesByName(ProcessName)[0];
            baseAddress = process.MainModule.BaseAddress;
            AddressLength = process.MainModule.ModuleMemorySize;
            ProcessID = process.Id;
            LinkHandle = OpenProcess(0x001F0FFF, 1, ProcessID);
            if (LinkHandle == IntPtr.Zero)
                throw new Win32Exception(Marshal.GetLastWin32Error());
        }

        public void Dispose()
        {
            process.Dispose();
            CloseHandle(LinkHandle);
        }

        public uint ReadUInt(uint Address)
        {
            byte[] buffer = new byte[4];
            if (ReadProcessMemory(LinkHandle, (IntPtr)Address, buffer, (uint)buffer.Length, IntPtr.Zero) == 0)
                throw new Win32Exception(Marshal.GetLastWin32Error());
            return BitConverter.ToUInt32(buffer, 0);
        }
        public byte[] ReadBytes(int Address, int byteCount)
        {
            byte[] buffer = new byte[byteCount];
            if (ReadProcessMemory(LinkHandle, (IntPtr)Address, buffer, (uint)buffer.Length, IntPtr.Zero) == 0)
                throw new Win32Exception(Marshal.GetLastWin32Error());
            return buffer;
        }
        public double ReadDouble(int Address)
        {
            byte[] buffer = new byte[8];
            if (ReadProcessMemory(LinkHandle, (IntPtr)Address, buffer, (uint)buffer.Length, IntPtr.Zero) == 0)
                throw new Win32Exception(Marshal.GetLastWin32Error());
            return BitConverter.ToInt64(buffer, 0);
        }

        public void WriteUInt(uint Address, uint Value)
        {
            if (!WriteProcessMemory(LinkHandle, (IntPtr)Address, BitConverter.GetBytes(Value), 4, IntPtr.Zero))
                throw new Win32Exception(Marshal.GetLastWin32Error());
        }
    }
}

//fill in the process you want to hack
MemoryManager memoryManager = new MemoryManager("ProcessName");
//read an integer from the provided memory address
uint value = memoryManager.ReadUInt(0x009D3FD0);
//write an integer to the provided address
memoryManager.WriteUInt(0x009D3FD0, 123);
//dispose the manager
memoryManager.Dispose();