This should be done before the branch-off, and can be done by anyone, as the steps are easily reproducible and reviewable.

#### Useful skills:

* Building Bitcoin Core
* Follow the documentation: https://github.com/bitcoin/bitcoin/blob/master/doc/release-process.md#before-branch-off

#### Want to work on this issue?

For guidance on contributing, please read [CONTRIBUTING.md](https://github.com/bitcoin/bitcoin/blob/master/CONTRIBUTING.md) before opening your pull request.

{
    MaybeUpdateHeights(args, consensus);
    if (!args.IsArgSet("-vbparams")) return;
    for (const std::string& strDeployment : args.GetArgs("-vbparams")) {
        std::vector<std::string> vDeploymentParams = SplitString(strDeployment, ':');
        if (vDeploymentParams.size() < 3 || 4 < vDeploymentParams.size()) {
            throw std::runtime_error("Version bits parameters malformed, expecting deployment:start:end[:min_activation_height]");
        }
        int64_t nStartTime, nTimeout;
        int min_activation_height = 0;
        if (!ParseInt64(vDeploymentParams[1], &nStartTime)) {
            throw std::runtime_error(strprintf("Invalid nStartTime (%s)", vDeploymentParams[1]));
        }
        if (!ParseInt64(vDeploymentParams[2], &nTimeout)) {
            throw std::runtime_error(strprintf("Invalid nTimeout (%s)", vDeploymentParams[2]));
        }
        if (vDeploymentParams.size() >= 4 && !ParseInt32(vDeploymentParams[3], &min_activation_height)) {
            throw std::runtime_error(strprintf("Invalid min_activation_height (%s)", vDeploymentParams[3]));
        }
        bool found = false;
        for (int j=0; j < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++j) {
            if (vDeploymentParams[0] == VersionBitsDeploymentInfo[j].name) {
                UpdateVersionBitsParameters(Consensus::DeploymentPos(j), nStartTime, nTimeout, min_activation_height);
                found = true;
                LogPrintf("Setting version bits activation parameters for %s to start=%ld, timeout=%ld, min_activation_height=%d\n", vDeploymentParams[0], nStartTime, nTimeout, min_activation_height);
                break;
            }